First language if speak 2 languages Thai , English

[WilliamCave]

To start with I grew up with 2 languages French and English all my cousins are totally fluent in English and French both languages spoke at home.

A lot of my family have jobs in the govt be because they know 2 languages.

What would be ther mother tounge ?

As my kids have lived in Canada and Thailand, we speak Thai and English at home they know both languages , what would be there mother tounge then ?

[Mole]

I would consider both as their "native" tongue.

For example, I'm fluent in both Norwegian and Thai and consider both my "native" tongue.

I was born in Thailand and moved to Norway when I was 6 and grew up there and came back to Thailand when I was 19.

[zeichen]

Even though the person would be bilingual, I would still think that each person would still favor one language over the other. Rarely, would a person write notes to his/herself in both languages, or when they are thinking or doing soul searching in their mind. Their mental language would still be one or the other and not both.

You could argue both ways though that they have two mother tongues or that one is slightly more dominant.

[Mole]

For me, both Thai and Norwegian is equal.

I have no problems whatsoever expressing both languages and can speak both as a native. You wouldn't be able to tell if you spoke to me on the phone.

The same can not be said for my English, for instance, where I only have near fluency. There are still occasions where I struggle to find some words. I also speak with an accent.

[AyG]

What language do they dream in?

[kriswillems]

I am not fluent in Thai nor English.

I don't believe that people that are fluent in both languages, only think or dream in one language.

Even though I am not fluent I have conversations with people in my dream in Thai and English. When I stay in Europe I dream in my native language, when I stay in Thailand I dream in Thai and English. Dreams are usually based on the experience of that day, and if you never spoke your native language that day, it's probably unlikely that you will speak it in your dreams.