I have purchased your book and started signing with my 14mth old son when he was 7 months old. He was slow to pick it up but finally (after approx 4 months), when prompted, he signed 'Mum'. Then after that first time, he only signs when prompted ie: I say the word 'Mum', then he copies it. He is now signing 'Dad' and I think 'Sleep' but it's hard to tell if 'Sleep' is 'Sleep' or 'Mum'. He has only signed 'Eat' once when I said the word, but that is it. I know he understands and can do it, but he doesn't use it to communicate with us without being prompted. We use other signs like 'Ball', 'Book', 'Drink' and 'Milk'. Is he just lazy, or are we not consistent enough? Should we be introducing more words to keep him from getting bored?