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 couldn't calm you couldn't calm he couldn't calm we couldn't calm you couldn't calm they couldn't calm
V-ing form
I couldn't be calming you couldn't be calming he couldn't be calming we couldn't be calming you couldn't be calming they couldn't be calming
Perfect
I couldn't have calmed you couldn't have calmed he couldn't have calmed we couldn't have calmed you couldn't have calmed they couldn't have calmed
V-ing perfect
I couldn't have been calming you couldn't have been calming he couldn't have been calming we couldn't have been calming you couldn't have been calming they couldn't 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
couldn't I calm? couldn't you calm? couldn't he calm? couldn't we calm? couldn't you calm? couldn't they calm?
V-ing form
couldn't I be calming? couldn't you be calming? couldn't he be calming? couldn't we be calming? couldn't you be calming? couldn't they be calming?
Perfect
couldn't I have calmed? couldn't you have calmed? couldn't he have calmed? couldn't we have calmed? couldn't you have calmed? couldn't they have calmed?
V-ing perfect
couldn't I have been calming? couldn't you have been calming? couldn't he have been calming? couldn't we have been calming? couldn't you have been calming? couldn't they have been calming?