can exist
Regular verb: exist - existed- existed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can exist
you can exist
she can exist
we can exist
you can exist
they can exist 	I can be existing
you can be existing
she can be existing
we can be existing
you can be existing
they can be existing	I can have existed
you can have existed
she can have existed
we can have existed
you can have existed
they can have existed	I can have been existing
you can have been existing
she can have been existing
we can have been existing
you can have been existing
they can have been existing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot exist
you cannot exist
she cannot exist
we cannot exist
you cannot exist
they cannot exist 	I cannot be existing
you cannot be existing
she cannot be existing
we cannot be existing
you cannot be existing
they cannot be existing	I cannot have existed
you cannot have existed
she cannot have existed
we cannot have existed
you cannot have existed
they cannot have existed	I cannot have been existing
you cannot have been existing
she cannot have been existing
we cannot have been existing
you cannot have been existing
they cannot have been existing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I exist?
can you exist?
can she exist?
can we exist?
can you exist?
can they exist? 	can I be existing?
can you be existing?
can she be existing?
can we be existing?
can you be existing?
can they be existing? 	can I have existed?
can you have existed?
can she have existed?
can we have existed?
can you have existed?
can they have existed? 	can I have been existing?
can you have been existing?
can she have been existing?
can we have been existing?
can you have been existing?
can they have been existing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not exist?
can you not exist?
can she not exist?
can we not exist?
can you not exist?
can they not exist? 	can I not be existing?
can you not be existing?
can she not be existing?
can we not be existing?
can you not be existing?
can they not be existing? 	can I not have existed?
can you not have existed?
can she not have existed?
can we not have existed?
can you not have existed?
can they not have existed? 	can I not have been existing?
can you not have been existing?
can she not have been existing?
can we not have been existing?
can you not have been existing?
can they not have been existing?