I could perforate you could perforate he could perforate we could perforate you could perforate they could perforate
V-ing form
I could be perforating you could be perforating he could be perforating we could be perforating you could be perforating they could be perforating
Perfect
I could have perforated you could have perforated he could have perforated we could have perforated you could have perforated they could have perforated
V-ing perfect
I could have been perforating you could have been perforating he could have been perforating we could have been perforating you could have been perforating they could have been perforating
Negation
Simple form
I could not perforate you could not perforate he could not perforate we could not perforate you could not perforate they could not perforate
V-ing form
I could not be perforating you could not be perforating he could not be perforating we could not be perforating you could not be perforating they could not be perforating
Perfect
I could not have perforated you could not have perforated he could not have perforated we could not have perforated you could not have perforated they could not have perforated
V-ing perfect
I could not have been perforating you could not have been perforating he could not have been perforating we could not have been perforating you could not have been perforating they could not have been perforating
Interrogative form
Simple form
could I perforate? could you perforate? could he perforate? could we perforate? could you perforate? could they perforate?
V-ing form
could I be perforating? could you be perforating? could he be perforating? could we be perforating? could you be perforating? could they be perforating?
Perfect
could I have perforated? could you have perforated? could he have perforated? could we have perforated? could you have perforated? could they have perforated?
V-ing perfect
could I have been perforating? could you have been perforating? could he have been perforating? could we have been perforating? could you have been perforating? could they have been perforating?
Interro-negative form
Simple form
could I not perforate? could you not perforate? could he not perforate? could we not perforate? could you not perforate? could they not perforate?
V-ing form
could I not be perforating? could you not be perforating? could he not be perforating? could we not be perforating? could you not be perforating? could they not be perforating?
Perfect
could I not have perforated? could you not have perforated? could he not have perforated? could we not have perforated? could you not have perforated? could they not have perforated?
V-ing perfect
could I not have been perforating? could you not have been perforating? could he not have been perforating? could we not have been perforating? could you not have been perforating? could they not have been perforating?