could disappear
Regular verb: disappear - disappeared- disappeared

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could disappear
you could disappear
she could disappear
we could disappear
you could disappear
they could disappear 	I could be disappearing
you could be disappearing
she could be disappearing
we could be disappearing
you could be disappearing
they could be disappearing	I could have disappeared
you could have disappeared
she could have disappeared
we could have disappeared
you could have disappeared
they could have disappeared	I could have been disappearing
you could have been disappearing
she could have been disappearing
we could have been disappearing
you could have been disappearing
they could have been disappearing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't disappear
you couldn't disappear
she couldn't disappear
we couldn't disappear
you couldn't disappear
they couldn't disappear 	I couldn't be disappearing
you couldn't be disappearing
she couldn't be disappearing
we couldn't be disappearing
you couldn't be disappearing
they couldn't be disappearing	I couldn't have disappeared
you couldn't have disappeared
she couldn't have disappeared
we couldn't have disappeared
you couldn't have disappeared
they couldn't have disappeared	I couldn't have been disappearing
you couldn't have been disappearing
she couldn't have been disappearing
we couldn't have been disappearing
you couldn't have been disappearing
they couldn't have been disappearing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I disappear?
could you disappear?
could she disappear?
could we disappear?
could you disappear?
could they disappear? 	could I be disappearing?
could you be disappearing?
could she be disappearing?
could we be disappearing?
could you be disappearing?
could they be disappearing? 	could I have disappeared?
could you have disappeared?
could she have disappeared?
could we have disappeared?
could you have disappeared?
could they have disappeared? 	could I have been disappearing?
could you have been disappearing?
could she have been disappearing?
could we have been disappearing?
could you have been disappearing?
could they have been disappearing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I disappear?
couldn't you disappear?
couldn't she disappear?
couldn't we disappear?
couldn't you disappear?
couldn't they disappear? 	couldn't I be disappearing?
couldn't you be disappearing?
couldn't she be disappearing?
couldn't we be disappearing?
couldn't you be disappearing?
couldn't they be disappearing? 	couldn't I have disappeared?
couldn't you have disappeared?
couldn't she have disappeared?
couldn't we have disappeared?
couldn't you have disappeared?
couldn't they have disappeared? 	couldn't I have been disappearing?
couldn't you have been disappearing?
couldn't she have been disappearing?
couldn't we have been disappearing?
couldn't you have been disappearing?
couldn't they have been disappearing?