Therapist: “Where does grandma work?”
Little boy: “Um… she works at the house.”
“No. Where does grandma work? Say ‘library’.”
“Whee! Now you get a starburst.”
This is not how you teach three year olds to communicate in language.
Communicating is not about saying what you think other people want you to say. Communicating is about connecting thoughts to words the best you can and saying them (or typing them, or pick your pleasure).
This is not how you teach a kid “the woman who gives me many cookies works in a big building full of stories, which is awesome” this is how you teach a kid “when people tell me “blah blah blah” I should say “blah blah BLEE blah”.”
And this shows how, even “playful nice aversive-free” ABA is about having the kid be right, and not having the kid be a kid who mixes up “house” and “library”, or calls a library a “bookhouse”, or thinks Grandma’s “work” is baking him cookies. Don’t you want to say, “What does she do at the house?” and hear him say “Gives me cookies” and see him light up, and smile with him, or maybe he’ll tell you she stacks the books at the house and you can say “I think she does that at the library.” in a nice way, and also a way that actually teaches him something, because the way you’re doing it he just knows he’s wrong, and he doesn’t know why.
Being a little kid shouldn’t be about wrong and right. If a kid tells you he’s found a portal to fairyland, you aren’t supposed to say “No”, you’re supposed to say “Take me with you”.