I could rank you could rank he could rank we could rank you could rank they could rank
V-ing form
I could be ranking you could be ranking he could be ranking we could be ranking you could be ranking they could be ranking
Perfect
I could have ranked you could have ranked he could have ranked we could have ranked you could have ranked they could have ranked
V-ing perfect
I could have been ranking you could have been ranking he could have been ranking we could have been ranking you could have been ranking they could have been ranking
Negation
Simple form
I couldn't rank you couldn't rank he couldn't rank we couldn't rank you couldn't rank they couldn't rank
V-ing form
I couldn't be ranking you couldn't be ranking he couldn't be ranking we couldn't be ranking you couldn't be ranking they couldn't be ranking
Perfect
I couldn't have ranked you couldn't have ranked he couldn't have ranked we couldn't have ranked you couldn't have ranked they couldn't have ranked
V-ing perfect
I couldn't have been ranking you couldn't have been ranking he couldn't have been ranking we couldn't have been ranking you couldn't have been ranking they couldn't have been ranking
Interrogative form
Simple form
could I rank? could you rank? could he rank? could we rank? could you rank? could they rank?
V-ing form
could I be ranking? could you be ranking? could he be ranking? could we be ranking? could you be ranking? could they be ranking?
Perfect
could I have ranked? could you have ranked? could he have ranked? could we have ranked? could you have ranked? could they have ranked?
V-ing perfect
could I have been ranking? could you have been ranking? could he have been ranking? could we have been ranking? could you have been ranking? could they have been ranking?
Interro-negative form
Simple form
couldn't I rank? couldn't you rank? couldn't he rank? couldn't we rank? couldn't you rank? couldn't they rank?
V-ing form
couldn't I be ranking? couldn't you be ranking? couldn't he be ranking? couldn't we be ranking? couldn't you be ranking? couldn't they be ranking?
Perfect
couldn't I have ranked? couldn't you have ranked? couldn't he have ranked? couldn't we have ranked? couldn't you have ranked? couldn't they have ranked?
V-ing perfect
couldn't I have been ranking? couldn't you have been ranking? couldn't he have been ranking? couldn't we have been ranking? couldn't you have been ranking? couldn't they have been ranking?