could calm
Regular verb: calm - calmed- calmed

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