Question

1. You must be honest.
2. You have to be honest.
(Situation: The person is not honest, so the boss is scolding the man.)

3. You must be honest.
4. You have to be honest.
5. I am sure that you are honest.
(The man was honest, and the boss knows it, so he said this way.)
----------------------------
Q 1: Can we use 'have to' instead of 'must' in the sentences above?

Q 2: They have different meaning though they have the same sentences? Right?
Would you help me with this matter?

Answer 1

Q. 1 Yes

Q. 2 All of the sentences mean the same.

Answer 2

In each case, the pronunciation of the words in each sentence will convey the meaning. Here's how:

1. You <b>must</b> be honest.
2. You <b>have</b> to be honest.
(Situation: The person is not honest, so the boss is scolding the man.)
[Pronounce the words in bold more loudly than the other words in each sentence.]

3. You must be <b>honest</b>.
4. You are obviously <b>honest</b>.
5. I am <b>sure</b> that you are <b>honest</b>.
(The man was honest, and the boss knows it, so he said this way.)
[Pronounce the words in bold more loudly than the other words in each sentence.]

Let us know if this doesn't make sense, but sometimes pronunciation is the only way to tell the differences in meanings.