First language, mother tongue, or native speaker?

I’ve always found it interesting that some words and phrases, even when they have almost identical dictionary definitions, are interpreted differently by different groups of people, and even different individuals.  Sometimes I am sure that a word means a certain thing (because it’s always been used that way amongst people I associate with), and am very surprised to hear that it has different or alternative definitions in the dictionary.

Before I get carried away, I’d like to talk about an interesting Linguaphiles discussion I saw on LiveJournal yesterday.  The original poster asked people what they thought the difference was between a first language, a mother tongue, and being a native speaker.  According to narcissus1, and the Oxford Advanced Learners Dictionary:

… mother tongue and first language both refer to the language you acquire as a child and are most fluent in. When we use these words in everyday speech, do they include any connotations of race, culture and background? For example, if a person is Japanese does it necessarily mean that their mother tongue is Japanese? What about second and third (etc) generation immigrants who have lost the language of their parents?

Another question is, who do you call a ‘native speaker’? Again, OAL says that a native speaker is one who speaks a language as a first language. I’ve always considered English as my first language simply because it’s the language I’m most fluent in. But in my country English functions as a second language, and as a result I’ve never considered myself a native speaker of English.

A lot of the commenters seem to think that mother tongue is different from the other two, in that it carries the idea of culture and ethnicity.  I tend to agree with this, and I think that’s why it’s not commonly used as an official term any more.

I consider myself a native speaker of English, and wouldn’t hesitate to say that it was my first language.  I would say that Cantonese was my mother tongue, as my parents speak it, and I spoke it when I was very young.  My Cantonese is not very good nowadays, but should I then consider it a second language?  Was Cantonese equally my first language?

Read the full discussion for more interesting interpretations.  I’d also be interested to hear about other people’s views and experiences.