What differences are there between using the present tense 'have', future tense 'will have', and the future progressive tense 'will be having' in the following two sentences (one statement and one question):
1) I HAVE/ WILL HAVE / WILL BE HAVING a test tomorrow morning.
My thoughts: 'Will have' seems to be the least likely option as it indicates a sudden decision of wanting to take a test as opposed to sitting a scheduled event planned in advance. 'Have' is definitely more common than 'will be having', yet I don't see any problems with the latter. So why is that the case???
2) Does anyone know when we WILL BE HAVING / WILL HAVE/ HAVE the test?
My thoughts: My ear tells me using 'have' here is grammatically incorrect, as the sentence calls for the usage of future tense in that position. What I find hard to distinguish however are the other two. When should I choose 'will be having' over 'will have' and vice versa???
Many thanks in advance.