Tegan, this will vary ALOT! At 20mths Lindsay had quite a few words and was just beginning to talk in sentences, but Erin was talking alot earlier and seemed very far ahead of Lindsay at the same age. Paige still doesn't talk and only has a very few words. She babbles in sentences and has the same sounds when talking about certain things, ie she always uses the same sound for dog. So I suppose real words will follow soon. But don't get too worried if you think Lily is a bit slower than others around the same age her as they will do it in their own time. Once they start there's no stopping them!