All are grammatical in some contexts. Though the distinction is fading away,
"will" is used in the indicative mood
"shall" is the imperative mood
(reversed in first person)
1. It will be Chris.
2. It shall be Chris.
*3. It will have been Chris.
*4. It shall have been Chris.
5. It would have been Chris.
6. It should have been Chris.
7. It can be Chris.
*8. It can have been Chris.
9. It could have been Chris.
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Does #1 mean #2? What is the difference in meaning? Are #3, #4, and #8 ungrammatical?
What is the difference between #5 and #6?
2 answers
Steve is right.
#8 is not ungrammatical, but having a present tense auxiliary verb is very strange. This would not be used very often, if at all.
#8 is not ungrammatical, but having a present tense auxiliary verb is very strange. This would not be used very often, if at all.