Yes, even if you don't tell him to speak first. This way he will be able to associate the word "speak" with barking.

It's the same concept as if I'm trying to teach my pup "bring". I can't MAKE her bring me the toy without doing it myself, and then I'm just confusing her more, and she's not learning anything. But if I say "GOOD BRING!!" and act stupidly excited when she just walks in my direction with a toy in her mouth, she will start to associate "bring" with bringing toys to me.