One Parent One Language Research Paper

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Shawn Ford
ESL 380
Summer '00

Note: The following article was written as aproject for SLS 380, instructed by Steven Talmy of the Department of SecondLanguage Studies at the University of Hawai‘i at Manoa. Please pardon anyerrors or omissions. Refer to the References section for additional information on the topic.

Language Mixing among Bilingual Children



The subject of language mixing is of great interest to researchers who study childhood bilingual development and to parents of bilingual children. A large amount of the research in this area has attempted to explain language mixing as a natural result of predictable developmental stages. In addition, researchers have attempted to address concerns about developmental problems related to language mixing.

For the parents of bilingual children, languagemixing is often seen as evidence of confusion due to the simultaneousacquisition of two languages; therefore, language mixing is a problem that mustbe corrected. Unfortunately, this attitude may sometimes lead to monolingualismin the attempt to correct this misperceived problem.

My own personal interest in this topic stems from mydesire to raise my newborn daughter Hannah as a bilingual speaker of Englishand Japanese. Throughout her development towards bilingualism over the nextseveral years, Hannah will probably mix her two languages. I would like toprepare myself for this eventuality through this research project in the process of conducting my study, I will keep inmind several important research questions:

• How common is language mixing among bilingualchildren?

• How valid is Taeschner's bilingual developmentmodel?

• Is language mixing a problem?

Definition oflanguage mixing

Language mixing is the term used to describe thephenomenon of communication though the usage of two languages as if they wereone language. In the literature available on childhood bilingualism, it isdifficult to find an exact definition for language mixing. In fact, severalsources make its definition unclear and confusing. Within the seven sourcesused as reference for this paper, only one contained a clear and exactdefinition of language mixing. Arnberg states:

"Language mixing refers to the young child'smixing of both languages within the same utterance before the child is really aware of having two languages inits environment." (1987:27) (emphasis in original)


This definition will be applied throughout this paperwhenever the term language mixing is used, unless otherwise noted.


This definition of language mixing makes it clear thatthe mixing occurs among children during the time before they differentiate andseparate their two languages. The mixing is unconscious and is used by thechild without regard of their interlocutor's understanding of both languages(Arnberg, 1987). The children are simply using words that they have acquired tocommunicate their needs at the given moment.

The term language mixing is also used in reference toadult bilinguals. However, in this reference, the definition is entirelydifferent. When used to explain the speech phenomenon of specific adults,language mixing is a conscious use of a blend of two languages whereinterlocutors understand both languages. An example of adult language mixingwould be the Puerto Rican community in New York which mixes English and Spanish(Baker, 1996). Language mixing should not be confused with language switching,which is an entirely different matter that this paper will not cover.

The confusion over the definition of language mixingresults from the misuse or misrepresentation of the term by reputableresearchers in the field of language acquisition. The most notable examplecomes from Baker when he states, "Language mixing is given other labels:transference (i.e. transfer between the two languages); code switching (a termregularly used by researchers); and a related term, interference betweenlanguages," (1995: 77-78).

Having established this paper's working definition oflanguage mixing, the next step is to briefly explain its occurrence during thedevelopment of the child's languages.

Taeschner'sbilingual development model

Several researchers have attempted to develop a modelto explain the processes involved during the simultaneous acquisition of twolanguages in early childhood. The most comprehensive to date come from Baker(1995) and from Taeschner (in Harding &, Riley, 1986). However, Teaschner's1983 model is considered to be the most influential (Dopke, 1992).

Taeschner's model of early childhood bilingualdevelopment proposes that children pass through three phases throughout theprocess of acquiring their languages. While each phase includes certaincharacteristics, the lines between the phases are unclear. The ages of childrenin each phase may vary as well as the characteristics. Some children may stayin one phase longer than other children, and some characteristics may becarried over into another phase.

In the first phase, the bilingual child has onelexical system which represents both of the languages that they are acquiring.Where pairs of words from the different languages have the same meaning, thechild has not made this distinction. The child often uses the two words as ifthey have completely different meanings. For instance, a child may use “bowl”for their food bowl and osara (bowl) forall other bowls (Harding &, Riley, 1986).

Additionally, in this phase, children often blendwords from the two different languages into one word for one specific meaning.An example given by Harding &, Riley is the utterance "bitte-please" (1986: 51).

During the second phase of development, the child isbeginning to separate their vocabularies. They begin using the appropriatelanguage for each parent. The child has separated the pairs of words into theirown respective language instead of combining them into one meaning. However,the child's language still usually reflects one grammar system. An example ofthis grammar system would be the child uttering, "That is dishdoggie," instead of, "That is doggie's dish." (Baker, 1995).

In the third phase of language development, the childhas achieved almost complete separation of the two languages. The child becomesincreasingly aware that they have two distinct languages. In addition, thechild will usually speak to people in the appropriate language. During thisphase, the child also begins to differentiate between the two grammar systemsof their languages. However, this process may develop over several years insome cases. (Baker, 1995).

Taeschner's bilingual development model is useful forobserving the stages that may occur during the process of a child acquiring twolanguages. Keeping these phases in mind, I studied several bilingual childrento determine if they could be placed within this model. The results point outsome of the advantages and weaknesses of a construct such as this.

Case studies

As a part of my research into language mixing amongbilingual children, I conducted three case studies of bilingual children. Thesubjects were chosen at random from among my acquaintances. I had no priorknowledge of their language mixing. All of these children currently live inHonolulu, Hawaii, with their families. In addition, all of these children arebilingual in the same two languages: English and Japanese.


I spent approximately one hour with each of the threefamilies at various locations, interviewing the parents and observing thechildren. The main interview questions were:

• What is the bilingual child's age?

• What are the mother's and father's first languages?

• What is the family language spoken most often?

• In which language is the bilingual child mostdominant?

• Does the bilingual child mix their languages?

• If so, how often? in what contexts? and, do youperceive this to be a problem?

I also asked other questions relating to day care, children'splaymates, the frequency of reading in either language, and any otherstrategies used by the family to promote bilingualism.

Subjects' Biographical Data

Subject's Name

Subject's Age

Developmental Stage

Bilingual Development

Father's L1

Mother's L1

Family Language


(1, 11)

Stage I

Japanese dominant






Stage 2

Mostly English






Stage 3

English dominant







Sky (1, 11) is a bilingual male whose parents areJapanese nationals. The first language of both parents is Japanese. They havelived in America for approximately five years and could be considered to haveintermediate English speaking ability. The family language used almostexclusively, except for a few borrowed English words, is Japanese. Sky's fatherinformed me that the family goal is to raise Sky as a productive bilingual.

Sky is most dominant in Japanese. Sky's mother is hisprimary care-giver. She spends time each day reading to him in Japanese. Skyalso watches Japanese animation on television and on video. He watches verylittle programming in English. According to his parents, he is exposed toJapanese an estimated 80 percent of the time. The other 20 percent of the timeis spent playing with his English-speaking friend next door.

Sky's parents informed me that he usually mixes histwo languages only when he is playing, with the exception of using borrowedEnglish words that he has learned from his parents. They assume that thereasoning for this is due to the time that Sky spends every day playing withhis English-speaking neighbor. Although Sky's parents do not feel that hislanguage mixing is a problem, they said that on occasion it causes confusionwhen he goes to his auntie's house; she speaks Japanese and very littleEnglish. While his auntie baby-sits him, Sky sometimes mixes his languages tothe extent that his auntie cannot understand him.

During my observation of Sky, I was able to find twoexamples of his language mixing. Both of these examples involved play. Thefirst example was when he was given a box of miscellaneous toys. He immediatelypicked up a small toy truck and said, "Oh, chuck!" Next he found acar to which he said, "Ca!" Then he began to crash the two toys intoone another while yelling, "Bon! Bon!" (the Japanese equivalent of"Bam!" or "Bang!"). His mother responded to his noise with,"Sky! Urusai!" ("Sky! Be quiet!") Sky then replied,"Chuck urusai." ("Truck is noisey.")

Sky's second example of language mixing occurred justbefore leaving the interview site. When Sky understood that he was about toleave, he went to his father and produced the following speech stream:

"Papa, dako! Antony uchi ikitai. Won play Antonyuchi." ("Papa, pick me up. I want to go to Anthony's house. I want toplay at Anthony's house.")

It is possible that Sky began this speech stream inJapanese because he wanted something from his father that he intimatelyassociated with his Japanese language; he wanted to be carried. Sky then mixed inEnglish when he thought about playing with his friend.

Based on this very limited information, Sky appearsto fall within Taeschner's first stage of bilingual development (in Dopke,1992). He uses both lexical systems as one language, and he speaks his mixedlanguage to different people. However, further observation is required toverify this categorization and Sky's amount of language mixing.


J.C. (2,9) is a bilingual male whose father was bornand raised in America and whose mother was born and raised in Japan. Hisfather's first language is English, yet he also speaks Japanese at an advancedlevel. The first language of J.C.'s mother is Japanese. She also speaksintermediate-level English. She has lived in America for approximately four anda half years.

According to J.C.'s mother, the family language usedmost frequently is English. However, she said that had not always been thecase. Until just before J. C. turned two years old, the family language wasmostly Japanese. Once J.C. began attending an English-speaking day care center,he started speaking almost exclusively in English. Consequently, his parentsmade the switch to English as the dominant family language.

J.C.'s mother also said that she stopped reading tohim around this time. She was concerned that he would get too confused if hewas being read to in English at the day care center and in Japanese at home. Inaddition, J.C. no longer watches Japanese television or videos. He now watchesalmost exclusively English programs. On the other hand, his mother said thatshe has tried to continue speaking to him in Japanese as much as possiblewhenever they are alone.

J.C.'s mother also informed me that the family has noexplicit goal to raise J.C. as a bilingual, although she would like him to bebilingual. This family seems to be more concerned that J.C. develops hisEnglish speaking skills. As a result, J.C. is exposed to English a majority ofthe time.

Currently, J.C. speaks mostly English, although,according to his mother, he understands 100 percent of what is said to him inJapanese. To clarify this point, J.C.'s mother asked him, "J.C. Onakasuita? Hirogohan o tabetai?" ("J.C. Are you hungry? Do you want toeat lunch?") J.C. responded, "No. I want some juice." Heunderstood her question in Japanese yet answered in English.

In addition to his English vocabulary, J.C.'s mothersaid that he also uses a large number of Japanese words where there is noEnglish equivalent or where he has learned to use a specific word for aspecific purpose. His language mixing seems to fall within these uses. AlthoughJ.C. clearly seems to be dominant in English, I would consider him bilingualbased on his understanding of spoken Japanese and his use of many Japaneselexical items. However, J.C. most likely faces a high risk of losing hisJapanese- speaking ability unless his family takes corrective steps to reversethis trend.

During my observation of J.C., I was able to observeonly one example of language mixing. Noticing a scrape on J.C.'s knee, my wifeasked him, "Ita so, J.C. Doo datta?" ("Looks painful, J.C. How'dyou do that?") J.C. replied, "Itai! I fell down." ("Ithurts! I fell down.")

Based on such limited information, it is difficult todetermine that either J.C. does not mix his languages very often, or that hewas just quiet on this particular day. However, it seems that J.C. could beplaced within Taeschner's second stage of bilingual development (in Dopke,1992). He seems to have separated the languages at this point, although hestill mixes the two languages when he uses words that he has learned to use forspecific items and in certain contexts.


Shinya (3,7) is a bilingual female who was born inJapan and moved to America with her parents approximately two years ago. Herfather was born and raised in America, and her mother was born and raised inJapan. The first language of Shinya's father is English, and he also speaksintermediate Japanese. He lived in Japan for almost four years as an Englishinstructor at Kanda University. The first language of Shinya's mother isJapanese. She also speaks English at the intermediate level and has lived inAmerica for approximately two years.

The family uses a mixed language strategy at home.According to Shinya's parents, they both speak English and Japanese to Shinyaand to each other throughout the day. There seems to be no clear association inthis family with language use and activity, situation, or time of day. However,the parents informed me that on a daily basis each parent reads to Shinya intheir respective first language. In addition, Shinya enjoys both English andJapanese television programs and videos.

This family has an explicit goal to raise Shinya as aproductive bilingual. However, Shinya is most dominant in English. This isprobably due to the fact that she attends an English-speaking day care.Although Shinya's parents believe that they speak to her in Japanese andEnglish an equal amount of the time when they are with her, they estimate thatshe receives only 20 to 25 percent of her language input in Japanese because ofher exposure to English at the day-care.

With regards to language mixing, Shinya's case seemsmost interesting. According to her parents, Shinya never noticeably mixed herlanguages until the past six months. However, recently they have noticed Shinyamixing her languages, especially in the evening when it approaches time for herto go to bed. Her mixing occurs most frequently while her parents are readingher bed-time story.

As an example her mother said that recently she wasreading one of Shinya's favorite Japanese stories about a rabbit. After readinga section where the rabbit jumps into its hole, Shinya asked her mother,"Doshite ushisan likes to live in the ground?" ("Why does Mr. Rabbitlike to live in the ground?") In this example Shinya seems to begin herquestion in Japanese as a continuation of her mother's speech but finishes inEnglish for another reason.

When asked if they perceive Shinya's language mixingto be a problem, both parents replied that it did not bother them. In fact,they seemed to find humor in her language mixing. They also made mention oftheir belief that language mixing in her case was natural. Their main interestwas regarding Shinya's beginning to mix her languages so late in herdevelopment. Her parent's attitudes may be the result of her father's trainingas an English teacher and knowledge of childhood language development.

During my observation of Shinya I was able to findseveral examples of her language mixing. The first example occurred soon aftershe arrived at the interview site. At one point, she jumped onto a futon wheremy two month old daughter was sleeping. Shinya's mother told her, "Abunai.Akachan wa nette iru no." ("Be careful. The baby is sleeping.")Shinya replied, "Akachan? Oh, akachan is sleeping." ("Baby? Oh,the baby is sleeping.")

In the next example, while we were eating dinner,Shinya's mother asked her, "Shinya, dooshite supagetti o tabenai no?Supagetti wa oishii." ("Shinya, why aren't you eating the spaghetti?The spaghetti tastes good.) Shinya's reply was, "No! Spaghetti wa mazui! Iwanna eat more corn." ("No! The spaghetti tastes bad! I want to eatmore corn.")

In a third example, just before leaving the interviewsite, Shinya jumped onto her father and said, "I wanna go home, Papa.Nemutai. I wanna go to bed." ("I want to go home, Papa. I'm tired. Iwant to go to bed.")

In each of these examples, Shinya mixed lexical itemsfrom Japanese into her predominantly English speech streams. Throughout thisbrief observation period, only these few examples of language mixing occurred.Most of her speech streams were in English only. It is interesting to note thather language mixing occurred when her speech was directed at her parents. At notime during the interview did she mix her languages while speaking to the otherpeople in the room.

Shinya seems to fit within Taeschner's third stage ofbilingual development (in Dopke, 1992). She appears to have control of bothlanguages and separation has occurred. Shinya also seems to know which languageto speak with which person.

Her situation is most interesting to me because shehas only begun to mix her languages after reaching three years of age. Sheseems to have skipped the first and second stages of Taeschner's model andlanded solidly in the third stage. While Shinya's case may not be consistentwith Taeschner's model, it is somewhat more consistent with Goodz's research(in Genesee, 1994). In this research, Goodz found that language mixing amongbilingual children occurred very little at younger ages, but it peaked between31 to 36 months old (66). Shinya would have been approximately 37 months oldwhen her parents began noticing her mix her languages. In light of this,Shinya's case deserves further study.


It is difficult to reach any clear conclusions aboutlanguage mixing and bilingual children after conducting such a brief study.This area of language research is so varied and complex that it deservesextensive examination into all facets of the subject. However, my limitedlanguage study has produced some important points to consider.

Among the subjects I studied, language mixing amongbilingual children is a common phenomenon. This is interesting to note becausethe subjects were chosen at random among my acquaintances, and I had no priorknowledge of their language mixing. Although all three subjects mixed theirlanguages, they all varied in the amounts of their language mixing, thecontexts of their language mixing, and the developments of their languagemixing. These findings highlight the need for further research into this area.Research questions that should be asked include:

• What are factors thatcause some children to mix their languages more than others?

• Why do children mix their languages in specificcontexts?

• Why do some childrenvary so greatly in their language development with regards to language mixing?

The attitudes of the parents of bilingual childrenare very important when it concerns language mixing. The perception of languagemixing as a problem can negatively effect the child's bilingual development. Aswas the case with J.C., once he began speaking English more and mixing his twolanguages, his parents' concern caused them to radically alter their family languagepattern. This has resulted in J.C.'s lower fluency in Japanese.

I would stress the need for more public awarenessabout childhood bilingual development, in particular the issue of languagemixing. If parents understand that language mixing is a natural part of theirchild's language development, maybe parents will be less inclined to reactnegatively and instead provide more support for their developing child. Thenperhaps the future will see more bilingually productive adults.

While conducting my research into the study oflanguage mixing, Iachieved high levels of confusion over its definition and itsdistinction from language switching. Severalresearchers seem to use the two terms interchangeably. This presents a problemfor the novice.

A study of the relevant literature would beinteresting to search for the uses of language mixing and language switching. If this study were conducted, perhaps findings wouldencourage researchers in the field of bilingualism to be more careful in theirchoice and use of these terms consistently.

Regarding Taeschner's bilingual development model andthose of other researchers who have attempted to conveniently spell outparticular phases that children grow through in the process of simultaneouslyacquiring two languages, these types of models appear to provide only a roughguideline for parents and other researchers to follow. While Taeschner's modelseems to include many bilingual development issues and to describe a processthrough which bilingual children may go, I feel that models such as thisover-generalize the subject. Taeschner's model makes no exceptions for childrensuch as Shinya whose parents claim that she did not mix her languages untilreaching the age of three.

I would suggest that much more extensive researchinto the subject of childhood bilingual development is necessary. In addition,perhaps in this case what is needed is a more comprehensive presentation ofinformation, issues, and possible results instead of a simplistic model thatdoes not account for exceptions. I feel that this would be a more useful toolfor other researchers and for parents of bilingual children who are looking foranswers to their questions regarding their children's bilingual development.



Arnberg, L. (1987). RaisingChildren Bilingually: The preschool years. Clevedon:Multilingual Matters.

Baker, C. (1995). AParent's and Teacher's Guide to Bilingualism. Clevedon:Multilingual Matters.

Baker, C. (1996). Thedevelopment of bilingualism. Foundations of Bilingual Education andBilingualism (2nd Ed.), (pp. 76-93).Clevedon: Multilingual Matters.

Cunningham-Andersson, U.& Andersson, S. (1999). Growing Up with Two Languages: A practicalGuide. London: Rutledge.

Dopke, S. (1992). OneParent One Language: An interactional approach. Amsterdam: John Benjamins Publishing.

Goodz, N. (1994).Interactions between parents and children in bilingual families. In F. Genesee(Ed.) Educating Second Language Children: The whole child, the wholecurriculum, the whole community. New York:Cambridge UP.

Harding, E. & Riley,P. (1986). The Bilingual Family: A handbook for parents. Cambridge: Cambridge UP.


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contents (c) 2001 Shawn Ford/ Webb-Ed Press

A well-known approach used with children who are acquiring two languages simultaneously is for each parent to use his or her own language with their child. Thus, for example, parent 1 will use Spanish and parent 2 English. This is known as the one person­–one language strategy or OPOL.

The strategy has probably been around since the beginning of intermarriages between people belonging to different language groups. In recent times, however, its onset has a precise date: 1908. It was in that year that a baby boy, Louis, was born to the Ronjat family in France. Jules Ronjat was a French linguist who had a German wife and they wanted to bring up their son bilingual. So Jules asked a colleague, Maurice Grammont, who had done some research on language development, for his advice.

Grammont replied soon after Louis' birth and Jules Ronjat cites ten lines of his letter in a book he was to write about Louis' bilingualism in 1913. Grammont told Jules that each language must be represented by a different person. Thus, Jules would always speak French to Louis, and his wife German, without ever reversing the pattern.

Jules Ronjat's book was read by many linguists, among them Werner Leopold in the United States in the 1930s who decided, with his wife, Marguerite, to use this approach with their own child, Hildegard. Leopold spoke German to her and Marguerite, English, and Hildegard did grow up bilingual, although dominant in English. Hildergard's bilingual development is well-known in the linguistic world as her father, himself a linguist, wrote four volumes in English on her dual language acquisition. Since then, the one person–one language approach has been used continuously and is reported on in the majority of books dealing with the simultaneous acquisition of two languages.  

The approach is very appealing to parents who wish to nurture bilingualism in their children from the start, to the point that some people talk of the one parent (not person)–one language rule or principle. It allows parents to use their dominant language with their child which may also be their language of emotion (see here for a post on the topic). With this dual input, children very quickly produce sounds, syllables, and words in each language, and are remarkably good at knowing which language to use with which parent.

However, as time goes by, problems often start appearing. Since exposure to the two languages is rarely equal, especially when the child starts interacting with the outside world, the language with less input, often the minority language, suffers. If, in addition, the parent who speaks it is bilingual, then the child may well start responding in the other, stronger, language. In the end, the child may only retain receptive skills in the weaker language.

The success rate of the approach has been studied, most notably by researcher Annick De Houwer who reports in her study of 2,000 families that a full quarter of the children brought up with the approach did not become bilingual (see here). When both parents spoke both languages to their children—something Grammont insisted they not do—the percentage of children who ended up bilingual was not significantly different!

I have often talked to parents who use the approach and many find it stressful to have to keep to one language with their child, as well as insist on getting a response in the weaker language, and others worry about what to do when the context calls for the other language (e.g. when they are outside the home). Parents often end up adapting the strategy to their own needs or simply shifting to another approach.

Over the years, researchers who discuss Grammont's approach have often referred to his 1902 book, Observations sur le langage des enfants (Observations on Children's Language). In my attempt to understand the underpinnings of his proposal, I looked for the book and, to my astonishment, found that it did not exist! Instead, there is a Festschrift, with a different title, honoring the French linguist, Antoine Meillet, which contains a chapter by Grammont with that title. So I went to the archives of the University of Geneva library and took it out. Grammont's contribution does indeed discuss the language development of two French-speaking children but it has nothing on bilingualism, and nothing on the one person–one language approach! In sum, his original proposal had no theoretical or scientific underpinning, at least published, and was stated in just ten lines in his letter to Ronjat!

Of course, the one person–one language approach deserves to continue being an option for parents. But at the very least, it should be adapted (when that is not already the case) and a family plan should be set up which takes into account important considerations such as what is the best strategy for that particular family, when should the languages be acquired, will the child have a real need for each language, what will be the type and amount of input from each language, and what other support can the parents count on (see here). Parents also have to work out how much of the other language each can use with their child (Hildegard often heard her father speak English!) and how much switching between languages can take place (there is no proof that intermingling languages affects language learning in the long run). 

The final word goes to Suzanne Hauwaert-Barron who has written a book on the approach and has used it with her own children: "I do wonder sometimes if it is the best method. Perhaps being able to switch effectively and know when to use each language in context is really the best tool we can give our children in the long term."

For a full list of "Life as a bilingual" blog posts by content area, see here.

Photo of father and son from Shutterstock.


- De Houwer, Annick (2007). Parental language input patterns and children's bilingual use. Applied Psycholinguistics, 28, 411-424.

- Ronjat, Jules (1913). Le développement du langage observé chez un enfant bilingue. Paris: Edouard Champion. 

- Barron-Hauwaert, Suzanne (2004). Language Strategies for Bilingual Families: The One-Parent-One-Language Approach. Bristol / Buffalo / Toronto: Multilingual Matters.

François Grosjean's website.


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