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