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