If it would make you feel better about little kids speaking Bulgarian....well, my partner feels very much the same when our little daughter comes back from nursery and starts talking to him in Bulgarian, it does take some time for her to switch to English and only after she has been reminded at least 10 times to do it. Gary finds it funny and annoying in the same time when he tries really hard to put a sentence together and then she repeats it with a smile on her face in a matter of 2 seconds:)))