My youngest had a full set of signals she had thought up herself to communicate with us, but, she did not speak. When she started speaking, she went really fast in picking it up.
Now, she is one of those kids who never shut up. Today she was hyper, and talking in overdrive.
When she is really upset or hurt, she will be non-verbal for a while again. A notebook and a pen helps her to relax. She'll draw what she wants to tell. And not stressing about it helps her find back the use of words quicker I think. Sometimes she is in between, she has words, just can't say them, then she'll use he notebook to write words down.