English verb conjugation
COULD PASS

Regular verb: pass - passed - passed

Affirmation

Simple form	V-ing form
I could pass you could pass he could pass we could pass you could pass they could pass	I could be passing you could be passing he could be passing we could be passing you could be passing they could be passing
Perfect	V-ing perfect
I could have passed you could have passed he could have passed we could have passed you could have passed they could have passed	I could have been passing you could have been passing he could have been passing we could have been passing you could have been passing they could have been passing

Negation

Simple form	V-ing form
I couldn't pass you couldn't pass he couldn't pass we couldn't pass you couldn't pass they couldn't pass	I couldn't be passing you couldn't be passing he couldn't be passing we couldn't be passing you couldn't be passing they couldn't be passing
Perfect	V-ing perfect
I couldn't have passed you couldn't have passed he couldn't have passed we couldn't have passed you couldn't have passed they couldn't have passed	I couldn't have been passing you couldn't have been passing he couldn't have been passing we couldn't have been passing you couldn't have been passing they couldn't have been passing

Interrogative form

Simple form	V-ing form
could I pass? could you pass? could he pass? could we pass? could you pass? could they pass?	could I be passing? could you be passing? could he be passing? could we be passing? could you be passing? could they be passing?
Perfect	V-ing perfect
could I have passed? could you have passed? could he have passed? could we have passed? could you have passed? could they have passed?	could I have been passing? could you have been passing? could he have been passing? could we have been passing? could you have been passing? could they have been passing?

Interro-negative form

Simple form	V-ing form
couldn't I pass? couldn't you pass? couldn't he pass? couldn't we pass? couldn't you pass? couldn't they pass?	couldn't I be passing? couldn't you be passing? couldn't he be passing? couldn't we be passing? couldn't you be passing? couldn't they be passing?
Perfect	V-ing perfect
couldn't I have passed? couldn't you have passed? couldn't he have passed? couldn't we have passed? couldn't you have passed? couldn't they have passed?	couldn't I have been passing? couldn't you have been passing? couldn't he have been passing? couldn't we have been passing? couldn't you have been passing? couldn't they have been passing?