It all boils down to what kind of a cup is in question. But generally speaking, the toddlers are grown enough to drink from their best straw sippy cup as they prefer to switch from a spouted cup to a spoutless or straw.This is because the transition is much easier to master at that age. However, if you still aren’t quite sure, try to assist them in the initial times and try to observe whether they can handle the straw and also suck the drink without getting choked. And, if they don’t you’re good to go, otherwise, we recommend waiting for some more time.