could coincide
Regular verb: coincide - coincided- coincided

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could coincide
you could coincide
she could coincide
we could coincide
you could coincide
they could coincide 	I could be coinciding
you could be coinciding
she could be coinciding
we could be coinciding
you could be coinciding
they could be coinciding	I could have coincided
you could have coincided
she could have coincided
we could have coincided
you could have coincided
they could have coincided	I could have been coinciding
you could have been coinciding
she could have been coinciding
we could have been coinciding
you could have been coinciding
they could have been coinciding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't coincide
you couldn't coincide
she couldn't coincide
we couldn't coincide
you couldn't coincide
they couldn't coincide 	I couldn't be coinciding
you couldn't be coinciding
she couldn't be coinciding
we couldn't be coinciding
you couldn't be coinciding
they couldn't be coinciding	I couldn't have coincided
you couldn't have coincided
she couldn't have coincided
we couldn't have coincided
you couldn't have coincided
they couldn't have coincided	I couldn't have been coinciding
you couldn't have been coinciding
she couldn't have been coinciding
we couldn't have been coinciding
you couldn't have been coinciding
they couldn't have been coinciding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I coincide?
could you coincide?
could she coincide?
could we coincide?
could you coincide?
could they coincide? 	could I be coinciding?
could you be coinciding?
could she be coinciding?
could we be coinciding?
could you be coinciding?
could they be coinciding? 	could I have coincided?
could you have coincided?
could she have coincided?
could we have coincided?
could you have coincided?
could they have coincided? 	could I have been coinciding?
could you have been coinciding?
could she have been coinciding?
could we have been coinciding?
could you have been coinciding?
could they have been coinciding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I coincide?
couldn't you coincide?
couldn't she coincide?
couldn't we coincide?
couldn't you coincide?
couldn't they coincide? 	couldn't I be coinciding?
couldn't you be coinciding?
couldn't she be coinciding?
couldn't we be coinciding?
couldn't you be coinciding?
couldn't they be coinciding? 	couldn't I have coincided?
couldn't you have coincided?
couldn't she have coincided?
couldn't we have coincided?
couldn't you have coincided?
couldn't they have coincided? 	couldn't I have been coinciding?
couldn't you have been coinciding?
couldn't she have been coinciding?
couldn't we have been coinciding?
couldn't you have been coinciding?
couldn't they have been coinciding?