can sue
Regular verb: sue - sued- sued

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can sue
you can sue
he can sue
we can sue
you can sue
they can sue 	I can be suing
you can be suing
he can be suing
we can be suing
you can be suing
they can be suing	I can have sued
you can have sued
he can have sued
we can have sued
you can have sued
they can have sued	I can have been suing
you can have been suing
he can have been suing
we can have been suing
you can have been suing
they can have been suing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't sue
you can't sue
he can't sue
we can't sue
you can't sue
they can't sue 	I can't be suing
you can't be suing
he can't be suing
we can't be suing
you can't be suing
they can't be suing	I can't have sued
you can't have sued
he can't have sued
we can't have sued
you can't have sued
they can't have sued	I can't have been suing
you can't have been suing
he can't have been suing
we can't have been suing
you can't have been suing
they can't have been suing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I sue?
can you sue?
can he sue?
can we sue?
can you sue?
can they sue? 	can I be suing?
can you be suing?
can he be suing?
can we be suing?
can you be suing?
can they be suing? 	can I have sued?
can you have sued?
can he have sued?
can we have sued?
can you have sued?
can they have sued? 	can I have been suing?
can you have been suing?
can he have been suing?
can we have been suing?
can you have been suing?
can they have been suing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I sue?
can't you sue?
can't he sue?
can't we sue?
can't you sue?
can't they sue? 	can't I be suing?
can't you be suing?
can't he be suing?
can't we be suing?
can't you be suing?
can't they be suing? 	can't I have sued?
can't you have sued?
can't he have sued?
can't we have sued?
can't you have sued?
can't they have sued? 	can't I have been suing?
can't you have been suing?
can't he have been suing?
can't we have been suing?
can't you have been suing?
can't they have been suing?