Unschooling life. Learning without school. Call what you may like.
Children who are set free, choose what they want to learn at any moment.
5yo comes up and says, amma let's converse in English at home.
I, kind of forget to talk in English(at home) but not her.
I remember, being apprehensive about how kids can learn languages other than that spoken at home. As the elders are used to speak in the native language, ALL conversation at home happens in the mother tongue.
Now I have my 5yo who herself wants to talk in English at home and my 2yo who tells 3 lines of story in English and many other lines. All this, without me bringing any change in the language we communicate at home. Personally, I too, am used to speaking our native language at home and I also have read studies that say speaking in our mother tongue will keep us close to our intuition(more important for kids). If you notice, all the self-talk that you do with the subconscious happens in the mother tongue.
And, I remember we(13yo) had to pay a fine in our school for every time we do not speak in English!
Without the parent making any rules about language, children start an initiative and learn - precise and quick.