What is the understood question that Lennie wants George to ask Slim in Of Mice and Men?
When Lennie and George first meet the men with whom they'll be working, Carlson asks Slim how his dog is. Slim announces that she gave birth to puppies the night before. Then he goes on to say that she had nine of them, and since she couldn't feed that many, Slim went and drowned four of them right away. As Slim is talking about puppies, Lennie gets more and more excited, like he's going to burst. George sees Lennie's reaction to the news of puppies and knows exactly what he wants--a puppy to pet.
George has been with Lennie since they were kids, so he knows how much Lennie likes to pet anything with fur. At the beginning of the book the reader first encounters this when Lennie carries along a dead mouse simply because it's soft. With that character trait for Lennie already established, it is easy for the reader to infer what he means when George says, "I heard him, Lennie. I'll ask him" (36). Lennie wants George to ask Slim if he can have a puppy to pet.