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