1. What is he like?

- He is strong and tall.
- He is active and generous.

2. What does he look like?
- He is reserved and friendly.
- He is average height.

(Are they all grammatical? What is the difference between question 1 and Question 2?)

Question 1 seems to be asking more about his personality and character traits. Question 2 is asking about what he looks like ... height, coloring, etc.

Both of the answers for #1 are fine, but only the second answer for #2 is correct.

Thank you for your help...

3. What is he like?
- He is short and long hair.

Then is this answer acceptable as well?

These sentences would work with this question:

What is he like?

He is friendly and outgoing.
He is a very good student and spends lots of time in the library.
He is a very good athlete.

In other words, the answers need to focus on his personality and character, not his looks.

In re-reading my reply above, I see the error I made. Here's a correct explanation for you: Of the first two questions you posted, the first one elicits answers about his character, and the second one is expecting answers about his physical appearance.

Yes, all the sentences in both questions are grammatically correct.

The difference between question 1 and question 2 is that they are asking about different aspects of a person's characteristics.

Question 1 is asking about his personality traits. It asks "What is he like?", which implies that you want to know what his character or personality is like. The responses given describe his personality traits, such as being strong, tall, active, and generous.

Question 2, on the other hand, is asking about his physical appearance. It asks "What does he look like?", implying that you want to know about his physical features. The responses given describe his physical appearance, such as being reserved, friendly, and of average height.

In summary, question 1 focuses on his personality traits, while question 2 focuses on his physical appearance.