could validate
Regular verb: validate - validated- validated

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

Negation 	
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I could not validate
you could not validate
she 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
she could not be validating
we could not be validating
you could not be validating
they could not be validating	I could not have validated
you could not have validated
she 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
she 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 	Perfect 	V-ing perfect 	
could I validate?
could you validate?
could she validate?
could we validate?
could you validate?
could they validate? 	could I be validating?
could you be validating?
could she be validating?
could we be validating?
could you be validating?
could they be validating? 	could I have validated?
could you have validated?
could she 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 she 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 	Perfect 	V-ing perfect 	
could I not validate?
could you not validate?
could she 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 she not be validating?
could we not be validating?
could you not be validating?
could they not be validating? 	could I not have validated?
could you not have validated?
could she 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 she not have been validating?
could we not have been validating?
could you not have been validating?
could they not have been validating?