My DD is 11 months and still breastfeeding. I started her on a sippy around 6 months along with her solids. Originally, I started her on the ones with the silicone spout. She didn't seem to take to that too well, so I tried the kind with the silicone straw. She loved that one, but it took her a while to figure out how to use it. I tried her again on the silicone spout, and she decided that she liked it after all. THEN she figured out how to pinch the spout to 'milk' out her water... so now she uses the kind with a hard plastic spout. I did have to bribe her with diluted apple juice. (She really likes it, and I only gave it to her when she was constipated, so it was really a treat for her.) If it's something she REALLY likes, she will figure out how to get it out!!! lol.