So what age does the rapid accumulation of words usually start?

[GodzillasBumcheek]

And when does it stop FFS - i don't remember the other two being like this (though i'm sure they were at some point). And when do the coherent sentences start, approximately?

DS, 25 months, has gone from understanding loads but not saying much to a chatty little boy in the space of a couple of months! What a sponge! The latest trick is saying 'don't know' or 'don't like' to everything automatically, and catching himself when he works he does want some yoghurt etc after all! V. funny. .