DS is 18 months and understands and responds to whatever we say. However he only says 3 words I think, and probably noone else would understand them except us.
I dont think there is any problem with his understanding as we recently started baby signing with him as he seemed to be having a bit of a slow start talking and he has quickly picked up about 15 signs which he can use (if he remembers to).
My other children spoke well over 100 words very clearly by the age of 24 months, so only going by this I think DS may be a significantly delayed? Or do they come on really quickly when they ar ready?? I cant remember!!