I have to work tomorrow/I am supposed to work tomorrow.

[JaneGothic]

What is the difference?
I have to work tomorrow
I am supposed to work tomorrow

 

[emsr2d2]

What is the difference between the following sentences?
I have to work tomorrow.
I am supposed to work tomorrow.

As with your previous thread, there is a nuance of difference. The first is an obligation and the expectation is that you're going to do it. The second states that you should be going to work tomorrow. However, there's a good chance that it would be followed by "but ...".

I have to work tomorrow so I can't go to the cinema with you.
I'm supposed to work tomorrow but I guess I could call in sick and go to the cinema with you.

 

[jutfrank]

I should reiterate a very important point above concerning the meaning of 'be supposed to'. There is almost always a sense of 'but ...' with 'be supposed to'. In other words, there's almost always at least an implication that the expectation be not met in some way.

 

[Tarheel]

"I'm supposed to go to work tomorrow."

Nobody is ever going to say that unless they follow it with an explanation of why they're not going to work.