I could ascend you could ascend she could ascend we could ascend you could ascend they could ascend
V-ing form
I could be ascending you could be ascending she could be ascending we could be ascending you could be ascending they could be ascending
Perfect
I could have ascended you could have ascended she could have ascended we could have ascended you could have ascended they could have ascended
V-ing perfect
I could have been ascending you could have been ascending she could have been ascending we could have been ascending you could have been ascending they could have been ascending
Negation
Simple form
I couldn't ascend you couldn't ascend she couldn't ascend we couldn't ascend you couldn't ascend they couldn't ascend
V-ing form
I couldn't be ascending you couldn't be ascending she couldn't be ascending we couldn't be ascending you couldn't be ascending they couldn't be ascending
Perfect
I couldn't have ascended you couldn't have ascended she couldn't have ascended we couldn't have ascended you couldn't have ascended they couldn't have ascended
V-ing perfect
I couldn't have been ascending you couldn't have been ascending she couldn't have been ascending we couldn't have been ascending you couldn't have been ascending they couldn't have been ascending
Interrogative form
Simple form
could I ascend? could you ascend? could she ascend? could we ascend? could you ascend? could they ascend?
V-ing form
could I be ascending? could you be ascending? could she be ascending? could we be ascending? could you be ascending? could they be ascending?
Perfect
could I have ascended? could you have ascended? could she have ascended? could we have ascended? could you have ascended? could they have ascended?
V-ing perfect
could I have been ascending? could you have been ascending? could she have been ascending? could we have been ascending? could you have been ascending? could they have been ascending?
Interro-negative form
Simple form
couldn't I ascend? couldn't you ascend? couldn't she ascend? couldn't we ascend? couldn't you ascend? couldn't they ascend?
V-ing form
couldn't I be ascending? couldn't you be ascending? couldn't she be ascending? couldn't we be ascending? couldn't you be ascending? couldn't they be ascending?
Perfect
couldn't I have ascended? couldn't you have ascended? couldn't she have ascended? couldn't we have ascended? couldn't you have ascended? couldn't they have ascended?
V-ing perfect
couldn't I have been ascending? couldn't you have been ascending? couldn't she have been ascending? couldn't we have been ascending? couldn't you have been ascending? couldn't they have been ascending?