could operate
Regular verb: operate - operated- operated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could operate
you could operate
he could operate
we could operate
you could operate
they could operate 	I could be operating
you could be operating
he could be operating
we could be operating
you could be operating
they could be operating	I could have operated
you could have operated
he could have operated
we could have operated
you could have operated
they could have operated	I could have been operating
you could have been operating
he could have been operating
we could have been operating
you could have been operating
they could have been operating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not operate
you could not operate
he could not operate
we could not operate
you could not operate
they could not operate 	I could not be operating
you could not be operating
he could not be operating
we could not be operating
you could not be operating
they could not be operating	I could not have operated
you could not have operated
he could not have operated
we could not have operated
you could not have operated
they could not have operated	I could not have been operating
you could not have been operating
he could not have been operating
we could not have been operating
you could not have been operating
they could not have been operating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I operate?
could you operate?
could he operate?
could we operate?
could you operate?
could they operate? 	could I be operating?
could you be operating?
could he be operating?
could we be operating?
could you be operating?
could they be operating? 	could I have operated?
could you have operated?
could he have operated?
could we have operated?
could you have operated?
could they have operated? 	could I have been operating?
could you have been operating?
could he have been operating?
could we have been operating?
could you have been operating?
could they have been operating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not operate?
could you not operate?
could he not operate?
could we not operate?
could you not operate?
could they not operate? 	could I not be operating?
could you not be operating?
could he not be operating?
could we not be operating?
could you not be operating?
could they not be operating? 	could I not have operated?
could you not have operated?
could he not have operated?
could we not have operated?
could you not have operated?
could they not have operated? 	could I not have been operating?
could you not have been operating?
could he not have been operating?
could we not have been operating?
could you not have been operating?
could they not have been operating?