English verb conjugation
COULD VERIFY

Regular verb: verify - verified - verified

Affirmation

Simple form	V-ing form
I could verify you could verify he could verify we could verify you could verify they could verify	I could be verifying you could be verifying he could be verifying we could be verifying you could be verifying they could be verifying
Perfect	V-ing perfect
I could have verified you could have verified he could have verified we could have verified you could have verified they could have verified	I could have been verifying you could have been verifying he could have been verifying we could have been verifying you could have been verifying they could have been verifying

Negation

Simple form	V-ing form
I could not verify you could not verify he could not verify we could not verify you could not verify they could not verify	I could not be verifying you could not be verifying he could not be verifying we could not be verifying you could not be verifying they could not be verifying
Perfect	V-ing perfect
I could not have verified you could not have verified he could not have verified we could not have verified you could not have verified they could not have verified	I could not have been verifying you could not have been verifying he could not have been verifying we could not have been verifying you could not have been verifying they could not have been verifying

Interrogative form

Simple form	V-ing form
could I verify? could you verify? could he verify? could we verify? could you verify? could they verify?	could I be verifying? could you be verifying? could he be verifying? could we be verifying? could you be verifying? could they be verifying?
Perfect	V-ing perfect
could I have verified? could you have verified? could he have verified? could we have verified? could you have verified? could they have verified?	could I have been verifying? could you have been verifying? could he have been verifying? could we have been verifying? could you have been verifying? could they have been verifying?

Interro-negative form

Simple form	V-ing form
could I not verify? could you not verify? could he not verify? could we not verify? could you not verify? could they not verify?	could I not be verifying? could you not be verifying? could he not be verifying? could we not be verifying? could you not be verifying? could they not be verifying?
Perfect	V-ing perfect
could I not have verified? could you not have verified? could he not have verified? could we not have verified? could you not have verified? could they not have verified?	could I not have been verifying? could you not have been verifying? could he not have been verifying? could we not have been verifying? could you not have been verifying? could they not have been verifying?