could appear
Regular verb: appear - appeared- appeared

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could appear
you could appear
he could appear
we could appear
you could appear
they could appear 	I could be appearing
you could be appearing
he could be appearing
we could be appearing
you could be appearing
they could be appearing	I could have appeared
you could have appeared
he could have appeared
we could have appeared
you could have appeared
they could have appeared	I could have been appearing
you could have been appearing
he could have been appearing
we could have been appearing
you could have been appearing
they could have been appearing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't appear
you couldn't appear
he couldn't appear
we couldn't appear
you couldn't appear
they couldn't appear 	I couldn't be appearing
you couldn't be appearing
he couldn't be appearing
we couldn't be appearing
you couldn't be appearing
they couldn't be appearing	I couldn't have appeared
you couldn't have appeared
he couldn't have appeared
we couldn't have appeared
you couldn't have appeared
they couldn't have appeared	I couldn't have been appearing
you couldn't have been appearing
he couldn't have been appearing
we couldn't have been appearing
you couldn't have been appearing
they couldn't have been appearing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I appear?
could you appear?
could he appear?
could we appear?
could you appear?
could they appear? 	could I be appearing?
could you be appearing?
could he be appearing?
could we be appearing?
could you be appearing?
could they be appearing? 	could I have appeared?
could you have appeared?
could he have appeared?
could we have appeared?
could you have appeared?
could they have appeared? 	could I have been appearing?
could you have been appearing?
could he have been appearing?
could we have been appearing?
could you have been appearing?
could they have been appearing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I appear?
couldn't you appear?
couldn't he appear?
couldn't we appear?
couldn't you appear?
couldn't they appear? 	couldn't I be appearing?
couldn't you be appearing?
couldn't he be appearing?
couldn't we be appearing?
couldn't you be appearing?
couldn't they be appearing? 	couldn't I have appeared?
couldn't you have appeared?
couldn't he have appeared?
couldn't we have appeared?
couldn't you have appeared?
couldn't they have appeared? 	couldn't I have been appearing?
couldn't you have been appearing?
couldn't he have been appearing?
couldn't we have been appearing?
couldn't you have been appearing?
couldn't they have been appearing?