The sentence "I'm teaching two math classes tomorrow" is correct and sounds natural. It indicates a future plan or arrangement. As for the two sentences: 1. **"I just taught two classes."** This means you have already taught two classes in the recent past, implying that it happened very recently. 2. **"I just finished two classes."** This means that you have completed two classes recently, and it places more emphasis on the fact that the classes are now over. While the meanings are related, they aren't exactly the same: - "Taught" focuses on the action of teaching itself. - "Finished" emphasizes that the classes have concluded. So, while they are similar in meaning, "I just taught two classes" describes the action, and "I just finished two classes" describes the completion of that action.

Hi Lin. The first sentence is fine. "I just finished two classes" could mean you were a student or a teacher. "I just taught two classes" makes it clear you were a teacher.