can base
Regular verb: base - based- based

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can base
you can base
she can base
we can base
you can base
they can base 	I can be basing
you can be basing
she can be basing
we can be basing
you can be basing
they can be basing	I can have based
you can have based
she can have based
we can have based
you can have based
they can have based	I can have been basing
you can have been basing
she can have been basing
we can have been basing
you can have been basing
they can have been basing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't base
you can't base
she can't base
we can't base
you can't base
they can't base 	I can't be basing
you can't be basing
she can't be basing
we can't be basing
you can't be basing
they can't be basing	I can't have based
you can't have based
she can't have based
we can't have based
you can't have based
they can't have based	I can't have been basing
you can't have been basing
she can't have been basing
we can't have been basing
you can't have been basing
they can't have been basing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I base?
can you base?
can she base?
can we base?
can you base?
can they base? 	can I be basing?
can you be basing?
can she be basing?
can we be basing?
can you be basing?
can they be basing? 	can I have based?
can you have based?
can she have based?
can we have based?
can you have based?
can they have based? 	can I have been basing?
can you have been basing?
can she have been basing?
can we have been basing?
can you have been basing?
can they have been basing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I base?
can't you base?
can't she base?
can't we base?
can't you base?
can't they base? 	can't I be basing?
can't you be basing?
can't she be basing?
can't we be basing?
can't you be basing?
can't they be basing? 	can't I have based?
can't you have based?
can't she have based?
can't we have based?
can't you have based?
can't they have based? 	can't I have been basing?
can't you have been basing?
can't she have been basing?
can't we have been basing?
can't you have been basing?
can't they have been basing?