I could calm you could calm he could calm we could calm you could calm they could calm
V-ing form
I could be calming you could be calming he could be calming we could be calming you could be calming they could be calming
Perfect
I could have calmed you could have calmed he could have calmed we could have calmed you could have calmed they could have calmed
V-ing perfect
I could have been calming you could have been calming he could have been calming we could have been calming you could have been calming they could have been calming
Negation
Simple form
I could not calm you could not calm he could not calm we could not calm you could not calm they could not calm
V-ing form
I could not be calming you could not be calming he could not be calming we could not be calming you could not be calming they could not be calming
Perfect
I could not have calmed you could not have calmed he could not have calmed we could not have calmed you could not have calmed they could not have calmed
V-ing perfect
I could not have been calming you could not have been calming he could not have been calming we could not have been calming you could not have been calming they could not have been calming
Interrogative form
Simple form
could I calm? could you calm? could he calm? could we calm? could you calm? could they calm?
V-ing form
could I be calming? could you be calming? could he be calming? could we be calming? could you be calming? could they be calming?
Perfect
could I have calmed? could you have calmed? could he have calmed? could we have calmed? could you have calmed? could they have calmed?
V-ing perfect
could I have been calming? could you have been calming? could he have been calming? could we have been calming? could you have been calming? could they have been calming?
Interro-negative form
Simple form
could I not calm? could you not calm? could he not calm? could we not calm? could you not calm? could they not calm?
V-ing form
could I not be calming? could you not be calming? could he not be calming? could we not be calming? could you not be calming? could they not be calming?
Perfect
could I not have calmed? could you not have calmed? could he not have calmed? could we not have calmed? could you not have calmed? could they not have calmed?
V-ing perfect
could I not have been calming? could you not have been calming? could he not have been calming? could we not have been calming? could you not have been calming? could they not have been calming?