In grading tests, the official 'correct' answers with the textbook have deemed these two sentences incorrect. Your thoughts please.
"What will you do tomorrow if it's fine?"
""I will go shopping tomorrow with my brother."
(NB: These sentences ocurred independently on separate test papers they are not a question and answer from the same test.)
The 'correct' answers in both cases demand that "tomorrow" comes at the end of the sentence. While I agree that this structure would be more conventional in common spoken English, I'm not convinced that the above sentences are grammatically incorrect. Opinions please.
Welcome to English Forums, inoshishi!

Your question took an interesting and surprising turn at the end because I thought you were leading up to a question about the use of "will" vs. "going to"!

Perhaps "tomorrow" is slightly better in sentence-final position, but the difference is miniscule. I would put "tomorrow" in either of the two positions you suggest, but here's how I would phrase it:

What are you going to do tomorrow if the weather is good?*
What are you going to do if the weather is good tomorrow?

I'm [going / going to go] shopping with my brother tomorrow.
I'm [going / going to go] shopping tomorrow with my brother.
My brother and I are going shopping tomorrow.

*Personally, I don't tend to use "fine" in non-assertive contexts.


I don't think "usual" means "correct" but "Longman English Grammar" by L.G. Alexander (1988) says:

The most usual position of time adverbs is at the very end of a sentence.
"We checked in at the hotel on Monday/yesterday."
When there is more than one kind of adverb in a sentence, the usual position of adverbs of place is after manner, but before time.
"Barbara read quietly in the library all afternoon."
However, adverbs of direction can often come after movement verbs and before other adverbials.
"I went to London by train next day."

By the way I feel we can read the two sentences below differently.
[1] If the weather is good tomorrow, what shall we do?
[2] If the weather is good, what shall we do tomorrow?

Students: We have free audio pronunciation exercises.

How about the sentence, "I am flying to New York tomorrow with Cathay Pacific."? Should the "tomorrow" be put at the end of the sentence too? Thanks.
Thanks Jim. So there is no grammatical rule governing the placement of a time phrase in sentences like these, it's purely a matter of style/taste. This is what I felt too.
Re: will.../be going to... these tests were written by second and third grade Japanese JHS kids. They are taught both sentence patterns together as having the meaning of an intended future action. You're right that "I'm going to..." sounds more natural but these kids inevitably opt for the shorter (and therefore easier to remember) construction!
"...if the weather is fine" also wouldn't be my chosen phrase but again it's what they pick up from their (admittedly substandard) textbooks!
Students: Are you brave enough to let our tutors analyse your pronunciation?
 paco2004's reply was promoted to an answer.
Using "tomorrow" in the middle of the sentence and at the end of a sentence may make a change in its intended meaning. e.g.

a) What are you going to do about it if he decides to come tomorrow?

b) What are you going to do about it tomorrow if he decides to come?

'a' may imply "what are you going to do about it TODAY/NOW........" while 'b' doesn't imply that.