'must/have to' and 'going to/will'

[Petya]

Hello everyone,

Last week I had a serious disagreement with a colleague over my usage of 'have to' instead of 'must' and 'going to' instead of 'will'. I will give examples of the way I used them in that particular occasion. I used 'have to' to give instructions to my students, such as "You have to check the correct answer in this exercise", "You have to use the words to make a sentence." I also asked a couple of times: "What are you going to write in A?", "Which option are you going to choose?" (as a way of asking about their intention or decision based on the evidence from a reading or listening text). My colleague insists that I had to use "must" and "will" respectively and that I made grammar mistakes. Please, help me out here!
Thank you!

[Barb_D]

Welcome to the forums, Petya.

Your usage was fine. To use "must" instead of "have to" is also fine. Not better. Not the only correct way. Just "equally good."

To be honest, more natural would be "Check the correct answer" and "Use these words to make a sentence" instead of either "you have to..." or "you must..."

[5jj]

Welcome to the forum, Petya.

Please try to restrict threads to one question at a time. The will/going to and the must/have to quations are best dealt with separately.

If no-one has dealt with it first, I'll look at the question when I return to the forum tomorrow. In the meantime, the short answer to your question is that what you said was acceptable.

(later) I see that Barb beat me to it.

[Petya]

Welcome to the forums, Petya.

Your usage was fine. To use "must" instead of "have to" is also fine. Not better. Not the only correct way. Just "equally good."

To be honest, more natural would be "Check the correct answer" and "Use these words to make a sentence" instead of either "you have to..." or "you must..."

Thank you both for the quick answer. Of course, I use the imperatives all the time (with young children it's the best way I believe). But sometimes, when I paraphrase my instructions, I tend to use "have to". If you have time, 5jj, to elaborate on 'will' and going to', I'll appreciate it. I read your article on Futurity in English and I think it is enlightening.
Again, thank you both for your time!

[5jj]

[QUOTE=Petya;876499 If you have time, 5jj, to elaborate on 'will' and going to', I'll appreciate it. I read your article on Futurity in English and I think it is enlightening.[/QUOTE]

If you have read my article, then I really have little of value to add.

I'll just say that there are many situations in which more than form is possible. Explanations in course books and grammar books often give the impression that there is only one 'correct' thing to say in any given situation. This is simply not true.

[Petya]

Thanks a lot!

(Just for the record, I just spotted something wrong in my post and as a non-native speaker I feel guilty and quite eager to correct my own mistake. I should have written "on that particular occasion".)

[billmcd]

Reference the previous responses and maybe you should suggest that your "colleague" join the forum and post reason(s) for his/her opinion.