could celebrate
Regular verb: celebrate - celebrated- celebrated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could celebrate
you could celebrate
he could celebrate
we could celebrate
you could celebrate
they could celebrate 	I could be celebrating
you could be celebrating
he could be celebrating
we could be celebrating
you could be celebrating
they could be celebrating	I could have celebrated
you could have celebrated
he could have celebrated
we could have celebrated
you could have celebrated
they could have celebrated	I could have been celebrating
you could have been celebrating
he could have been celebrating
we could have been celebrating
you could have been celebrating
they could have been celebrating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't celebrate
you couldn't celebrate
he couldn't celebrate
we couldn't celebrate
you couldn't celebrate
they couldn't celebrate 	I couldn't be celebrating
you couldn't be celebrating
he couldn't be celebrating
we couldn't be celebrating
you couldn't be celebrating
they couldn't be celebrating	I couldn't have celebrated
you couldn't have celebrated
he couldn't have celebrated
we couldn't have celebrated
you couldn't have celebrated
they couldn't have celebrated	I couldn't have been celebrating
you couldn't have been celebrating
he couldn't have been celebrating
we couldn't have been celebrating
you couldn't have been celebrating
they couldn't have been celebrating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I celebrate?
could you celebrate?
could he celebrate?
could we celebrate?
could you celebrate?
could they celebrate? 	could I be celebrating?
could you be celebrating?
could he be celebrating?
could we be celebrating?
could you be celebrating?
could they be celebrating? 	could I have celebrated?
could you have celebrated?
could he have celebrated?
could we have celebrated?
could you have celebrated?
could they have celebrated? 	could I have been celebrating?
could you have been celebrating?
could he have been celebrating?
could we have been celebrating?
could you have been celebrating?
could they have been celebrating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I celebrate?
couldn't you celebrate?
couldn't he celebrate?
couldn't we celebrate?
couldn't you celebrate?
couldn't they celebrate? 	couldn't I be celebrating?
couldn't you be celebrating?
couldn't he be celebrating?
couldn't we be celebrating?
couldn't you be celebrating?
couldn't they be celebrating? 	couldn't I have celebrated?
couldn't you have celebrated?
couldn't he have celebrated?
couldn't we have celebrated?
couldn't you have celebrated?
couldn't they have celebrated? 	couldn't I have been celebrating?
couldn't you have been celebrating?
couldn't he have been celebrating?
couldn't we have been celebrating?
couldn't you have been celebrating?
couldn't they have been celebrating?