There are many possibilities what it could mean. Present participles (like "making") have flexible meanings, so "what he is making" can mean many different things: "what he is currently in process of making" "what he plans to make" "what he habitually makes" "what he will make" In order to know which meaning is the correct one, you need context. Don't worry. It is not difficult at all. Context almost always makes the meaning obvious. If you would like, you can pick one of these four possibilities and I will show you a context where that choice would be the correct one.

The sentence "I wonder what he's making for dinner." implies that someone is guessing or trying to figure out what "he" is currently in the process of making. "He's making" uses the present continuous tense, which suggests that the action (making dinner) is happening right now. VERB -DOING WORD ""MAKING"" "I wonder" indicates curiosity or speculation, so the speaker is guessing what the person is currently preparing. The sentence expresses that "he" is cooking at the moment, and the speaker is guessing or curious about what the meal will be

The sentence: "I wonder what he's making for dinner." likely means the speaker is guessing or curious about what the person is currently preparing for dinner. Contexts: * If the person is in the kitchen right now, the sentence implies they are actively cooking, and the speaker is speculating. * It could also mean the speaker is pondering what the person plans to cook, depending on the situation. The meaning depends on context, but it most commonly refers to present action.

Sounds like either talking about the meal he will make for a dinner you're going to, or just a chat about someone who's making dinner.

The second option