could interrogate
Regular verb: interrogate - interrogated- interrogated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could interrogate
you could interrogate
she could interrogate
we could interrogate
you could interrogate
they could interrogate 	I could be interrogating
you could be interrogating
she could be interrogating
we could be interrogating
you could be interrogating
they could be interrogating	I could have interrogated
you could have interrogated
she could have interrogated
we could have interrogated
you could have interrogated
they could have interrogated	I could have been interrogating
you could have been interrogating
she could have been interrogating
we could have been interrogating
you could have been interrogating
they could have been interrogating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not interrogate
you could not interrogate
she could not interrogate
we could not interrogate
you could not interrogate
they could not interrogate 	I could not be interrogating
you could not be interrogating
she could not be interrogating
we could not be interrogating
you could not be interrogating
they could not be interrogating	I could not have interrogated
you could not have interrogated
she could not have interrogated
we could not have interrogated
you could not have interrogated
they could not have interrogated	I could not have been interrogating
you could not have been interrogating
she could not have been interrogating
we could not have been interrogating
you could not have been interrogating
they could not have been interrogating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I interrogate?
could you interrogate?
could she interrogate?
could we interrogate?
could you interrogate?
could they interrogate? 	could I be interrogating?
could you be interrogating?
could she be interrogating?
could we be interrogating?
could you be interrogating?
could they be interrogating? 	could I have interrogated?
could you have interrogated?
could she have interrogated?
could we have interrogated?
could you have interrogated?
could they have interrogated? 	could I have been interrogating?
could you have been interrogating?
could she have been interrogating?
could we have been interrogating?
could you have been interrogating?
could they have been interrogating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not interrogate?
could you not interrogate?
could she not interrogate?
could we not interrogate?
could you not interrogate?
could they not interrogate? 	could I not be interrogating?
could you not be interrogating?
could she not be interrogating?
could we not be interrogating?
could you not be interrogating?
could they not be interrogating? 	could I not have interrogated?
could you not have interrogated?
could she not have interrogated?
could we not have interrogated?
could you not have interrogated?
could they not have interrogated? 	could I not have been interrogating?
could you not have been interrogating?
could she not have been interrogating?
could we not have been interrogating?
could you not have been interrogating?
could they not have been interrogating?