Adverbial scope of ‘tomorrow’

If you'll permit me, I think you're a bit guilty of overanalyzing here.

First, there is a clear difference between both sentences: one begins with "tomorrow", the other ends with it. Yes, this might seem like an appallingly obvious statement but here's the rub: if a speaker meant to say "I have to work tomorrow" they would not say "tomorrow I have to work".

So the position of "tomorrow" certainly does affect the meaning of the statement. However (getting back to the issue of overanalyzing), I believe the affect is simply one of emphasis.

Your "have to" is a red herring.

So basically what you are saying is that both are grammatically sound then but 'I have to work tomorrow' is more commonly used?

"So basically what you are saying is that both are grammatically sound then but 'I have to work tomorrow' is more commonly used?"

Both are grammatically correct. Although I presume "I have to work tomorrow" is more common, I couldn't say for sure.

I can see them being used in different contexts - 'Do you want to go to the fair with me?' might be answered by, 'I can't, I have to work tomorrow.' Whereas, to the question, 'Did you enjoy your day doing nothing?' the reply might be, 'I did, but tomorrow I have to work.'

Both are grammatically correct. Both mean pretty much the same thing. If anything, there might be a small difference of emphasis:

"When are you working?"
"I have to work tomorrow."

"What are you doing tomorrow?"
"Tommorow, I have to work."

Even so, you could just as easily switch the two answers to the questions above and still be equally correct.

In English, well, in all languages, there are always many ways to say the same thing. This should come as no surprise. Life would be pretty boring if this weren't true.

This is no big deal, really. It works the same for most other adverbs:
"Gingerly, he tiptoed through the room"
"He tiptoed through the room gingerly, "

I feel ya.
I DO think they mean slightly different things, although end up meaning the same thing, anyway.
One is "I have an obligation to work" ; the other is "I have an obligation tomorrow"