can duck
Regular verb: duck - ducked- ducked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can duck
you can duck
she can duck
we can duck
you can duck
they can duck 	I can be ducking
you can be ducking
she can be ducking
we can be ducking
you can be ducking
they can be ducking	I can have ducked
you can have ducked
she can have ducked
we can have ducked
you can have ducked
they can have ducked	I can have been ducking
you can have been ducking
she can have been ducking
we can have been ducking
you can have been ducking
they can have been ducking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot duck
you cannot duck
she cannot duck
we cannot duck
you cannot duck
they cannot duck 	I cannot be ducking
you cannot be ducking
she cannot be ducking
we cannot be ducking
you cannot be ducking
they cannot be ducking	I cannot have ducked
you cannot have ducked
she cannot have ducked
we cannot have ducked
you cannot have ducked
they cannot have ducked	I cannot have been ducking
you cannot have been ducking
she cannot have been ducking
we cannot have been ducking
you cannot have been ducking
they cannot have been ducking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I duck?
can you duck?
can she duck?
can we duck?
can you duck?
can they duck? 	can I be ducking?
can you be ducking?
can she be ducking?
can we be ducking?
can you be ducking?
can they be ducking? 	can I have ducked?
can you have ducked?
can she have ducked?
can we have ducked?
can you have ducked?
can they have ducked? 	can I have been ducking?
can you have been ducking?
can she have been ducking?
can we have been ducking?
can you have been ducking?
can they have been ducking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not duck?
can you not duck?
can she not duck?
can we not duck?
can you not duck?
can they not duck? 	can I not be ducking?
can you not be ducking?
can she not be ducking?
can we not be ducking?
can you not be ducking?
can they not be ducking? 	can I not have ducked?
can you not have ducked?
can she not have ducked?
can we not have ducked?
can you not have ducked?
can they not have ducked? 	can I not have been ducking?
can you not have been ducking?
can she not have been ducking?
can we not have been ducking?
can you not have been ducking?
can they not have been ducking?