أنشئ حسابًا أو سجّل الدخول للانضمام إلى مجتمعك المهني.
Presumably you are asking if the speech of "bilingual" children is slower to develop than the speech of those who speak just the one language. If I have interpreted the question correctly and I apologise if I haven't, I would suggest that the speech of "bilingual" children would be slower to develop purely because of the "volume" of words that they would have to learn! However I should think that if they have the ability to learn two languages at the same time the delay in progress would be very little.
The question is grammatically incorrect.
