difference between mother tongue and first language

What is the difference between Mother Tongue and First Language? (5 angles that may be mind-blowing for some) Decoding Definitions Miniseries: Question #3

definition, miniseries

Explore the nuances in the difference between mother tongue and first language, and gain insights into how these reflect an individual’s cultural and linguistic identity.

Table of Contents

Welcome to the 3rd instalment of our Miniseries “Decoding Definitions”. I find it quite fascinating to observe the evolving responses to my two earlier articles within this Miniseries. In particular, I noticed that many of us are more interested in understanding the nuances within the difference between Second Language and Foreign Language in contrast to knowing more about the difference between First Language and Second Language. I would attribute this trend, at least in part, to the fact that many among us are primarily educators specialising in the teaching and learning of second / foreign languages.

Notwithstanding such, I thought I should reiterate the importance of understanding the various terms that we encounter in research, in relation to our actual experiences. Consider, for instance, the phenomenon of “language attrition”. By examining the definitions of first language and second language in terms of proficiency, we can observe how an individual’s first language at one point in time can transform into a second language at a different juncture.

While we may officially categorise our instruction as either within the domain of “second language” or “foreign language”, our learners’ linguistic backgrounds may be so variegated that we may not be able to really classify them based on reductionist principles. We need to develop a good awareness of the nuances in different terms to effectively understand our learners’ linguistic backgrounds, proficiency levels, and potential difficulties they may face during the learning process. Misinterpreting these terms can lead to erroneous presumptions about a learner’s language capabilities at the outset, obstructing the design of efficient teaching strategies. And so, this is why this Miniseries is continuing its journey for an extended period of time.

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Difference between mother tongue and first language from 5 angles

So, for this third article, I aim to offer a comprehensive response that directly addresses the definitions posed in this question: What is the difference between Mother Tongue and First Language?

I will address this question by considering possible definitions which distinguish both from 5 angles: 

  • Origin of the terms
  • Connotation with cultural and social identity
  • Emotional attachment
  • Proficiency level and frequency of use
  • Consistency over the life course

1. Origin of the terms: Mother Tongue (and Native Language) vs First Language

source, origin
Photo from Envato Elements / The point from which the water of a river originates

In my first article within this Miniseries which aims to distinguish between first language and second language, I highlighted the common perception that “mother tongue” is often regarded as interchangeable with “first language”. This association arises, in part, from defining “first language” within the dimension of language acquisition context, utilising the norms of a monolingual society, and assuming the primary caregiver to be the mother.

However, as we dig a little bit deeper to the contexts giving rise to both terms, we may notice the difference in nuances as what they imply. Let us first attend to the question: why does a term such as “mother tongue” refer to a language?

The equivalent of “tongue” in Latin is “lingua”, which can denote the tongue as an organ within the mouth, or as language and speech. As such, “mother tongue” was used initially as a metaphor to denote the language an individual acquires early life after birth from the mother (who is the primary caregiver), because it is the “language spoken by the mother”.  In other words, it is the “mother language”, or the language one is natively born into and who would potentially become a native speaker

We can, of course, argue that the primary caregiver is not necessarily the biological mother (Davies, 2003). Individuals can be subject to different life circumstances where the biological mother is not able to take on the role of the significant other (e.g. death, divorce). Furthermore, with the changing role of women in society, the role of caregiving can also be the father, a grandparent, a sibling or a full-time babysitter with no familial blood ties. Note that the language used by these other caregivers may not be the common language spoken by all parties. 

Nevertheless, the biological mother is still the predominant figure that becomes the primary caregiver of a newborn. As such, she becomes the major source of language input for the child and the main target interlocutor for meaning exchanges. In that sense, “mother tongue” becomes a fitting term to denote the linguistic code that characterises those exchanges – the primary language in which the mother interacts with the child. 

In contrast, the term “first language” was originally coined to quite literally refer to that one language individuals learn first during early childhood. This concept was established in distinction to the idea of a “second language” which denotes any additional language learned after the individual had already gained proficiency in their “first language” – if it ever happens.

In a world primarily shaped by monolingual ideologies in the past, this concept appeared rather straightforward: an individual, would learn one language from birth as a native tongue, often from their mother, serving as their first language. Following that, if the opportunity arose, they might acquire another language and become bilinguals. 

The critical question now arises: must the mother tongue be the first language? Or is the converse necessarily true: must the first language be a mother tongue? In the past, it would appear so. Given the limits of our understanding of different individual acquisition processes, it would appear that the first language that a child receives and acquires is the language spoken by the mother, such that “mother tongue” appears to be the “first language” without exception.

Undeniably, the reality we came to understand is a bit messier today (or that it has always been messy but ideologies blinded us to it back then). First, depending on the actual caregiving situation, the child may receive input of different language(s) and even dialect(s) or variety(ies) and thus acquiring them as first language(s) which are not the language(s) of the mother as strictly defined – therefore first language(s) which are not the mother tongue(s).

Second, the definition of an individual’s first language(s) can undergo changes over their lifetime, depending on the dimensions used to define it. However, when we apply the concept of “nativity” to define the “mother tongue” (the fundamental philosophy underpinning its original metaphor), these first language(s) may not necessarily coincide with the concept of a mother tongue.

2. Connotation with cultural and social identity

cultural identity
Photo from Envato Elements / A lady wearing a Thai traditional costume

Riding on the notion of “nativity” in the definition mother tongue, which draws connection between the language and the heritage of the communities in which the individual is relatively socially positioned, there can be a clear differentiation between an individual’s “mother tongue” and “first language”.

This position is articulated in UNESCO’s definition of “mother tongue” wherein it distinctly outlines the source of acquisition as the home and family environment.

Consequently, such a definition firmly associates the term with cultural and ethnic identity. It also naturally implies a sense of innate acquisition, almost as if the mother tongue were hereditary, passed down through generations.

“First language”, on the other hand, is a more generic concept that serves to describe a psycholinguistic reality more than a sociolinguistic one. It tends not to carry the same connotations of cultural and social identity.

For instance, due to unavoidable circumstances like immigration or adoption, an individual’s first language might differ from their ancestral language (i.e. the particular language spoken by the ethnic group the individual is usually associated with). It may be a result of formal education, adaptation to a new social environment, or conditioning through societal influence. 

Therefore, the concept of first language may appear to be more fluid and neutral; it is more a function of factors outside of the individual biological family’s cultural ontology.

3. Emotional attachment: Language that a person connects with emotionally

mother and baby emotional attachment
Photo from Envato Elements / The emotional attachment between the baby and the mother

With the connotations that are generally attached to mother tongue, it comes as no surprise that it evokes more emotional attachment to individuals as a concept as opposed to first language. For many individuals, the mother tongue is like a portal to their past, reminiscing familial traditions, childhood memories, and formative experiences. Thereby, when individuals refer to their mother tongue, they allude not only to a language, but a loaded construct that spins an intricate web of memories, experiences and emotional connection which invariably play a significant role in identity formation.

Where the individual’s first language(s) coincide with the mother tongue(s), there might be non-perceivable differences in terms of such attachment – although I would say that declaring a language as a mother tongue in relation to declaring the same language as a first language do feel different.

This may be most pronounced in the context of policy implementation, such as within education. Individuals may be subject to learning certain languages as a first language; usually these languages are the country’s official languages or the society’s dominant languages. In such cases, they may or may not coincide with individual mother tongues. Yet, individuals may not respond to such arrangement emotively. 

However, if individuals are institutionally mandated to learn a given language as a mother tongue, the messaging effect is completely different. This arrangement can trigger emotive responses and policy contestations, especially when the target language in question is actually not the strictly defined mother tongue from the perspective of the individuals concerned.

4. Proficiency level and frequency of use: the dominant language versus the language less used

measurement of proficiency level
Photo from Envato Elements / Bringing in the measurement of proficiency and frequency

Theoretically, when we encounter individuals describing their mother tongue(s) or first language(s), we would not make a clear differentiation between the two concepts. Majority of the time, we tend to expect an individual to be highly proficient in his/her mother tongue or first language, and probably be using it frequently (one key factor in maintaining the language).

I have argued earlier that proficiency and frequency are two important dimensions where people may define their “first language” as opposed to “second language”. On the other hand, scholars have also observed that individuals may also define their “mother tongue” based on proficiency and frequency (Skutnabb-Kangas, 2008; Skutnabb-Kangas & McCarty, 2010).

It would thus seem that there is thus no difference between mother tongue and first language when proficiency and frequency are used as the criteria for definition. However, by virtue of the epistemological constraints on the terms, we can argue that we are using our mother tongue as a first language or as a second language (or even foreign language) – depending on proficiency and frequency. In the scenario where an individual is no longer fluent in his/her identified mother tongue, we can express it as that individual using his/her mother tongue as a second language – the mother tongue has thereby de-linked from first language. 

Let us zoom in on heritage language (a term I plan to address in the future) learners: It is possible that the language they acquired first as a mother tongue is indeed the heritage language – also the language spoken by the mother. However, based on our understanding of heritage language learners, it is not uncommon for them to never acquire the heritage language till the proficiency level of a first language. In the most challenging circumstances, they may attain only minimal proficiency for basic communication and use it sparingly, effectively positioning it into something akin to a foreign language. In such scenarios, the language in question can still be considered a mother tongue but is certainly not their first language.

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5. Consistency over the life course

life course of a man
Photo from Envato Elements / Life course of a man

In relation to the earlier point, there are many social and linguistic factors that can change and impact on our construction of our personal identities. As such, when we define our mother tongue or first language using similar factors, we would probably conceive a very dynamic representation of how we may designate a particular language as mother tongue or first language. 

However, would it possible for us to define our mother tongue or first language as something resistant to change over the life course (i.e. not changed once defined)? In this regard, a mother tongue might be more durable in definition in contrast to the first language. Think about it: a mother tongue can be recognised as a childhood experience of a first language but can become a second language or even foreign language over the life course due to dramatic changes in proficiency level and frequency. Having experienced those changes, one may still recognise the same childhood language as the mother tongue.

Let me illustrate this with a scenario: a child born to Korean immigrants in USA may learn Korean as his/her mother tongue as it is the main home language. As part of growing up, the child attends educational institutions where English is mainly used for instruction. Given its status as an official and predominant language, the child acquires proficiency in English to the level of a first language. Over time, English becomes the child’s most comfortable, proficient, and preferred language – thereby, evolving into the effective “first language”. Korean became a distant memory where the child may or may not be able to use beyond basic conversations. However, Korean can still be recognised as a mother tongue, but probably not a first language.

Will the next generation of this child still identify with Korean as a mother tongue? Probably not. The descendants of this child who would probably not have a conducive environment to learn Korean at home, will thus not even experience Korean as a mother tongue. In that sense, a language shift has taken place and the “new” mother tongue would have shifted to English instead. Assuming that these descendants stay in USA and not migrate elsewhere, their identified mother tongue and first language would thus be consistent throughout their life course. 

Can we establish a definition of the first language that remains robust over time, potentially disconnected from the concept of the mother tongue, such that the first language is not the mother tongue? Theoretically, such a dimension does exist, though I would speculate (lacking concrete data) that it predominantly manifests in situations where the first language is a heritage language or a minority language. The particular dimension would be the sequence of acquisition.

To put it simply, if we define our first language(s) fundamentally just by virtue of the sequence in which we acquire the language(s) (e.g. usually only considered for those within early childhood), then this language or these languages would remain as such over the life course – even when we cease to use them or become incapable of using them. Generally, these languages usually also happen to be the mother tongue, though it is not completely impossible to have acquire other languages that are not regarded as the mother tongue based on all the earlier dimensions (e.g. when our babysitter’s language is different from the language we speak at home).

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I must say this has been quite a journey. Trust me, the attempt to tease out intricate differences between two terms that have been taken for granted to be so similar is not an easy task – akin to the difficult task of distinguishing between a language and a dialect. Further adding to the complexity, a bilingual or multilingual experiencing two languages or more since birth in varying degrees would find it almost impossible to categorise them scientifically based on current criteria. 

Notwithstanding such challenges, I hope I have somewhat foregrounded some easily overlooked details when we engage these terms in defining our language experiences. I also want to highlight that it is always a good intellectual habit to examine the implied meanings when researchers engage different terms in their studies (e.g. the choice of first language acquisition/attrition over mother tongue acquisition/attrition). 

Thank you for reading! If you like what you are reading, do subscribe to our mailing list to receive updated resources and tips for language educators. Please also feel free to provide us any feedback or suggestions on content that you would like covered.


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