Our son is now a very verbal two-year-old. In fact, he doesn’t even remember many signs due to lack of use. We still show him now and again and he’ll mimic in much better precision than he did when he was actually using them for communication, but you can tell he doesn’t recollect much of his former language.
We were out yesterday and a stranger thanked him for something. I prompted him to say, “You’re welcome,” and he signed to her instead of speaking. I remarked to my husband later in the day that although he has dropped most of his signs, he usually still signs his manners (i.e., Thank you, Please, Sorry). My husband believes it must have something to do with our son’s comfort with strangers. He went through a very shy, hide-his-face-behind-my-legs phase, but he’s mostly grown out of that. Chris’ comment made me realize though, that our son also still signs greetings, as in HELLO and GOODBYE.