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