The term first language is used for the language that the speaker speaks best; his/her second language then being the language he speaks less well than his first language.
Sometimes the term native language is used to indicate a language that a person is as proficient in as a natural-born inhabitant of that language's "base country", or as proficient as the average person who speaks no other language but that language.
Sometimes the term mother tongue or mother language is used for the language that a person learnt at home (usually from her parents). Children growing up in bilingual homes can according to this definition have more than one mother tongue.
In the context of population censuses conducted on the Canadian population, Statistics Canada defines mother tongue as "the first language learned at home in childhood and still understood by the individual at the time of the census." It is quite possible that the first language learned is no longer a speaker's dominant language. Young immigrant children, whose families have moved to a new linguistic environment may lose, in part or in totality, the language they first acquired (see language attrition).
The term "mother tongue" should not be interpreted to mean that it is the language of one's mother. In some paternal societies, the wife moves in with the husband and thus may have a different first language than the husband. Mother in this context probably originated from the definition of mother as source, or origin; as in mother-country or -land.
In some countries such as Kenya and India, "mother tongue" is used to indicate the language of one's ethnic group (ethnic tongue), in both common and journalistic parlance (e.g. 'I have no apologies for not learning my mother tongue', rather than one's first language. Also in Singapore, "mother tongue" refers to the language of one's ethnic group regardless of actual proficiency, while the "first language" refers to the English language, which is the lingua franca for most post-independence Singaporeans due to its use as the language of instruction in government schools and as a working language.
J. R. R. Tolkien in his 1955 lecture English and Welsh distinguishes the "native tongue" from the "cradle tongue", the latter being the language one happens to learn during early childhood, while one's true "native tongue" may be different, possibly determined by an inherited linguistic taste, and may later in life be discovered by a strong emotional affinity to a specific dialect (Tolkien personally confessed to such an affinity to the Middle English of the West Midlands in particular).
21 February has been proclaimed the International Mother Language Day by UNESCO on 17 November 1999.
Language as a human institution presupposes communication. Individuals who are mute or deaf must learn how to speak by using sign language. One characteristic of language is finding names for objects and persons within the child’s reach, so it is possible for a child to grasp, repeat and understand the world.
One´s mother tongue makes it possible for a child to take part in the knowledge of the social work. Another impact of the mother tongue is that it brings about the reflection and learning of successful social patterns of acting and speaking. It is basically responsible for differentiating the linguistic competence of acting.
But there are also many people who prefer to speak and communicate in their second language rather than their mother tongue. They feel more comfortable in the second language because their mother tongue might be very limited and does not provide a large number of words or expressions.
Language is a medium of communication within the family and society. Every tongue expresses the culture of society to the complete satisfaction of its members. The language an individual speaks is for him or her the most expressive and often the most beautiful of all languages.
If language is denied to anyone, the following experiment will show what happens. Frederick II, Holy Roman Emperor (1194-1250), ordered some orphans to be brought to the palace where they should be observed while being brought up. He arranged every kind of physical care for the babies, but banned any kind of verbal or emotional physical contact. Thus he tried to find out which language the infants would speak naturally.
It was expected that it would be either Hebrew, Greek or Latin, formerly regarded as the original languages. But it was none of these languages nor was it the language of the children’s parents - the children did not speak any language at all: they died.
This experiment shows, and it has been proved by several psychological studies, that language is not only a product of human life it is the prerequisite of it. Or in other words, human beings require a human relationship to survive. These children were neither exposed to non-verbal expressions of emotions such as gestures, nor to speech.
One can have two or more native languages, thus being a native bilingual or indeed multilingual. The order in which these languages are learned is not necessarily the order of proficiency. For instance, a French-speaking couple might have a daughter who learned French first, then English; but if she were to grow up in an English speaking country, she would likely be proficient in English. Another example is India, where most people speak more than one language.
The Brazilian linguist Cleo Altenhofen considers the denomination "mother tongue" in its general usage to be imprecise and subject to various interpretations that are biased linguistically, especially with respect to bilingual children from ethnic minority groups. He cites his own experience as a bilingual speaker of Portuguese language and Riograndenser Hunsrückisch, a German-rooted language brought to southern Brazil by the first German immigrants. In his case, like that of many children whose home language differs from the language of the environment (the 'official' language), it is debatable which language is his 'mother tongue'. Many scholars gave definitions of 'mother tongue' through the years based on common usage, the emotional relation of the speaker towards the language, and even its dominance in relation to the environment. However, all of these criteria lack precision.