could corrugate
Regular verb: corrugate - corrugated- corrugated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could corrugate
you could corrugate
he could corrugate
we could corrugate
you could corrugate
they could corrugate 	I could be corrugating
you could be corrugating
he could be corrugating
we could be corrugating
you could be corrugating
they could be corrugating	I could have corrugated
you could have corrugated
he could have corrugated
we could have corrugated
you could have corrugated
they could have corrugated	I could have been corrugating
you could have been corrugating
he could have been corrugating
we could have been corrugating
you could have been corrugating
they could have been corrugating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not corrugate
you could not corrugate
he could not corrugate
we could not corrugate
you could not corrugate
they could not corrugate 	I could not be corrugating
you could not be corrugating
he could not be corrugating
we could not be corrugating
you could not be corrugating
they could not be corrugating	I could not have corrugated
you could not have corrugated
he could not have corrugated
we could not have corrugated
you could not have corrugated
they could not have corrugated	I could not have been corrugating
you could not have been corrugating
he could not have been corrugating
we could not have been corrugating
you could not have been corrugating
they could not have been corrugating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I corrugate?
could you corrugate?
could he corrugate?
could we corrugate?
could you corrugate?
could they corrugate? 	could I be corrugating?
could you be corrugating?
could he be corrugating?
could we be corrugating?
could you be corrugating?
could they be corrugating? 	could I have corrugated?
could you have corrugated?
could he have corrugated?
could we have corrugated?
could you have corrugated?
could they have corrugated? 	could I have been corrugating?
could you have been corrugating?
could he have been corrugating?
could we have been corrugating?
could you have been corrugating?
could they have been corrugating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not corrugate?
could you not corrugate?
could he not corrugate?
could we not corrugate?
could you not corrugate?
could they not corrugate? 	could I not be corrugating?
could you not be corrugating?
could he not be corrugating?
could we not be corrugating?
could you not be corrugating?
could they not be corrugating? 	could I not have corrugated?
could you not have corrugated?
could he not have corrugated?
could we not have corrugated?
could you not have corrugated?
could they not have corrugated? 	could I not have been corrugating?
could you not have been corrugating?
could he not have been corrugating?
could we not have been corrugating?
could you not have been corrugating?
could they not have been corrugating?