I used this cup with my 9 month old and it took about a day and a half for him to learn to use the straw. The weighted straw is an excellent feature. However, like other reviewers have mentioned, the cup leaks a lot. If you spend some time ensuring that you have screwed the top on precisely, it may not leak. I don't always have time to do that and there are other cups out there with weighted straws that aren't as tricky.