No, not at all. He is full of new language—and full of himself—and he just doesn’t have time to let it all out slowly! It is not at all unusual for 3-year-olds to pronounce their words imperfectly, and it can often be difficult to understand them. Most of those pronunciation errors correct themselves in time with no therapy of any sort. Showing too much concern is more likely to hurt than to help. The last thing you want to do is make him anxious about the process of talking and listening.
Don’t hesitate to let him know that you don’t understand him, but try to handle it very matter-of-factly. Put the onus on yourself and say laughingly, "Grandmothers sometimes need to hear something two or three times before they understand it. Say it a little more slowly and I’ll get it.”
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.