can hammer
Regular verb: hammer - hammered- hammered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can hammer
you can hammer
she can hammer
we can hammer
you can hammer
they can hammer 	I can be hammering
you can be hammering
she can be hammering
we can be hammering
you can be hammering
they can be hammering	I can have hammered
you can have hammered
she can have hammered
we can have hammered
you can have hammered
they can have hammered	I can have been hammering
you can have been hammering
she can have been hammering
we can have been hammering
you can have been hammering
they can have been hammering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't hammer
you can't hammer
she can't hammer
we can't hammer
you can't hammer
they can't hammer 	I can't be hammering
you can't be hammering
she can't be hammering
we can't be hammering
you can't be hammering
they can't be hammering	I can't have hammered
you can't have hammered
she can't have hammered
we can't have hammered
you can't have hammered
they can't have hammered	I can't have been hammering
you can't have been hammering
she can't have been hammering
we can't have been hammering
you can't have been hammering
they can't have been hammering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I hammer?
can you hammer?
can she hammer?
can we hammer?
can you hammer?
can they hammer? 	can I be hammering?
can you be hammering?
can she be hammering?
can we be hammering?
can you be hammering?
can they be hammering? 	can I have hammered?
can you have hammered?
can she have hammered?
can we have hammered?
can you have hammered?
can they have hammered? 	can I have been hammering?
can you have been hammering?
can she have been hammering?
can we have been hammering?
can you have been hammering?
can they have been hammering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I hammer?
can't you hammer?
can't she hammer?
can't we hammer?
can't you hammer?
can't they hammer? 	can't I be hammering?
can't you be hammering?
can't she be hammering?
can't we be hammering?
can't you be hammering?
can't they be hammering? 	can't I have hammered?
can't you have hammered?
can't she have hammered?
can't we have hammered?
can't you have hammered?
can't they have hammered? 	can't I have been hammering?
can't you have been hammering?
can't she have been hammering?
can't we have been hammering?
can't you have been hammering?
can't they have been hammering?