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 couldn't verify you couldn't verify he couldn't verify we couldn't verify you couldn't verify they couldn't verify	I couldn't be verifying you couldn't be verifying he couldn't be verifying we couldn't be verifying you couldn't be verifying they couldn't be verifying
Perfect	V-ing perfect
I couldn't have verified you couldn't have verified he couldn't have verified we couldn't have verified you couldn't have verified they couldn't have verified	I couldn't have been verifying you couldn't have been verifying he couldn't have been verifying we couldn't have been verifying you couldn't have been verifying they couldn't 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
couldn't I verify? couldn't you verify? couldn't he verify? couldn't we verify? couldn't you verify? couldn't they verify?	couldn't I be verifying? couldn't you be verifying? couldn't he be verifying? couldn't we be verifying? couldn't you be verifying? couldn't they be verifying?
Perfect	V-ing perfect
couldn't I have verified? couldn't you have verified? couldn't he have verified? couldn't we have verified? couldn't you have verified? couldn't they have verified?	couldn't I have been verifying? couldn't you have been verifying? couldn't he have been verifying? couldn't we have been verifying? couldn't you have been verifying? couldn't they have been verifying?