DD toe-walked until VERY late (she was still doing this occasionally at 4-6yo), and also went through an echolalia-like phase.
It was very disconcerting. Anytime DD says something... er... odd, for lack of a better word, just... something that isn't in HER voice, if that makes sense...
I know to ask "Where did that come from?" Now, she's self-aware enough to tell me. Not so much when she was 2 or 3, though. She would use whole chunks of language (phrases, sentences, or even more) contextually-appropriately, but I could often identify where she got them from. (Books, TV shows, conversation, the radio, etc.)
I don't think that other people noticed it as much; even DH doesn't pick up on it the way that I do. I'm more sensitive to 'voice' in spoken and written communication than most people, though-- this has been quite a handy thing in ferreting out plagiarism over the years, I must say. Because she used them appropriately, it was like a super-charged version of language acquisition operating on the context model, not true echolalia.
It's possible that this behavior (which DD also did for a time) is more about "did I hear you correctly?" and not something else. This only made sense to me when DD was older and we realized just how impaired her hearing was when she was <2.5 yo and had basically continuous ear infections and congestion. No wonder she was using what in an adult would be considered "mirroring," and seeking confirmation that we were understanding one another!!
