Sometimes a child does not speak in Gan (or some other specific environment), although he speaks at home. Adults often think that he is just shy and will outgrow it, but this is rarely the case. If a child does not speak in Gan, he may have a condition called "Selective Mutism" which is usually caused by anxiety. Without appropriate intervention, a child with Selective Mutism is likely to remain quite in school for years.
If your child is not speaking in Gan or at school, it is important to consult an expert.
For more information, call Shlomo Golub at +972-58-711-3238.
An interesting note: In Israel, Selective Mutism seems to be far more common amongst Chardi children than other children. The reason for this is not clear.