Ds1 who talked very early and has always spoken clearly and fluently has suddenly started stammering. He stammers a bit on individual letters but mostly on phrases so he repeats each part of the sentence several times before moving onto the next one. It started mildly a few weeks ago and seemed mostly when he was trying to find the right words for a difficult idea or concept but now seems to have spread to nearly all his speech. My gut feeling is that it is a phase that he will grow out of but I wondered if anyone had any experience of this or any advice. We haven't said anything to him about it in case of reinforcing it.