English verb conjugation
COULD VALIDATE

Regular verb: validate - validated - validated

Affirmation

Simple form	V-ing form
I could validate you could validate he could validate we could validate you could validate they could validate	I could be validating you could be validating he could be validating we could be validating you could be validating they could be validating
Perfect	V-ing perfect
I could have validated you could have validated he could have validated we could have validated you could have validated they could have validated	I could have been validating you could have been validating he could have been validating we could have been validating you could have been validating they could have been validating

Negation

Simple form	V-ing form
I could not validate you could not validate he could not validate we could not validate you could not validate they could not validate	I could not be validating you could not be validating he could not be validating we could not be validating you could not be validating they could not be validating
Perfect	V-ing perfect
I could not have validated you could not have validated he could not have validated we could not have validated you could not have validated they could not have validated	I could not have been validating you could not have been validating he could not have been validating we could not have been validating you could not have been validating they could not have been validating

Interrogative form

Simple form	V-ing form
could I validate? could you validate? could he validate? could we validate? could you validate? could they validate?	could I be validating? could you be validating? could he be validating? could we be validating? could you be validating? could they be validating?
Perfect	V-ing perfect
could I have validated? could you have validated? could he have validated? could we have validated? could you have validated? could they have validated?	could I have been validating? could you have been validating? could he have been validating? could we have been validating? could you have been validating? could they have been validating?

Interro-negative form

Simple form	V-ing form
could I not validate? could you not validate? could he not validate? could we not validate? could you not validate? could they not validate?	could I not be validating? could you not be validating? could he not be validating? could we not be validating? could you not be validating? could they not be validating?
Perfect	V-ing perfect
could I not have validated? could you not have validated? could he not have validated? could we not have validated? could you not have validated? could they not have validated?	could I not have been validating? could you not have been validating? could he not have been validating? could we not have been validating? could you not have been validating? could they not have been validating?