I could offer you could offer she could offer we could offer you could offer they could offer
V-ing form
I could be offering you could be offering she could be offering we could be offering you could be offering they could be offering
Perfect
I could have offered you could have offered she could have offered we could have offered you could have offered they could have offered
V-ing perfect
I could have been offering you could have been offering she could have been offering we could have been offering you could have been offering they could have been offering
Negation
Simple form
I could not offer you could not offer she could not offer we could not offer you could not offer they could not offer
V-ing form
I could not be offering you could not be offering she could not be offering we could not be offering you could not be offering they could not be offering
Perfect
I could not have offered you could not have offered she could not have offered we could not have offered you could not have offered they could not have offered
V-ing perfect
I could not have been offering you could not have been offering she could not have been offering we could not have been offering you could not have been offering they could not have been offering
Interrogative form
Simple form
could I offer? could you offer? could she offer? could we offer? could you offer? could they offer?
V-ing form
could I be offering? could you be offering? could she be offering? could we be offering? could you be offering? could they be offering?
Perfect
could I have offered? could you have offered? could she have offered? could we have offered? could you have offered? could they have offered?
V-ing perfect
could I have been offering? could you have been offering? could she have been offering? could we have been offering? could you have been offering? could they have been offering?
Interro-negative form
Simple form
could I not offer? could you not offer? could she not offer? could we not offer? could you not offer? could they not offer?
V-ing form
could I not be offering? could you not be offering? could she not be offering? could we not be offering? could you not be offering? could they not be offering?
Perfect
could I not have offered? could you not have offered? could she not have offered? could we not have offered? could you not have offered? could they not have offered?
V-ing perfect
could I not have been offering? could you not have been offering? could she not have been offering? could we not have been offering? could you not have been offering? could they not have been offering?