when we weaned out LO, she was much yonger (about 4 months) but what we were told is that we would just have to keep trying different bottles until we found one she liked. What we found worked that best was the natural shape, either Gerber or Playtex. However, with an 11 month old, it would probably be more appropriate to go right to a sippy cup, but I'm assuming the same advice: Just keep trying different brands until your baby finds one they like.