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