The problem with teaching kids manners too early to young children with autism is that instead of using the item name (cookie) and asking for “cookie,” the child might reach for a cookie and say “please” instead. A parent or teacher might then give the child a cookie because he used nice manners but the child may not know the name of the item or be able to say it.
Here’s what I recommend instead: It’s much more meaningful and important for a child to be able to request an item, for example, “cookie,” than for us to try to make them say “please,” which is really abstract and usually a meaningless word to young, early learners with autism.
Once your child can request items, in this case, “cookie,” it would be more useful to work on them being specific with their request. For example, “chocolate chip cookie” or “sugar cookie” are more meaningful and specific than “cookie, please” where “please” isn’t actually adding more information which would help the child communicate what they want to others.