Most of the time we know exactly what he means.

Puh puh puh church, he said, over and over again. Except the "church" part sounded like tut. And it was fairly out of context, as he sat building with magnatiles. So it took us a long time to understand what he was actually saying. 

When he gets frustrated because we don't understand, he tries to enunciate the initial sound, but it's always with the letter P, whether the word starts with P or not. Like puh puh puh diving board. Or puh puh puh solution. 

So, not particularly helpful. But super cute.