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