I was going to say books... then music.

I have read to my DD every day since she was born. She loves story time.

I also sing repeatative songs with her that have actions.... like "This is the way we wash our face (etc)"... she actually does the motions in the bath now and she is only 1... it helps heaps me too, might I add...

Reading, repeatition, and read anything. My daughter likes books like the Hairy Macleary range or anything that has a grandad in it. She is obsessive about her Grandad. Also books like The Very Hungry Caterpillar are brilliant because they include science (life cylce of a butterfly), types of food, counting, and can be interactive.