can clerk
Regular verb: clerk - clerked- clerked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can clerk
you can clerk
she can clerk
we can clerk
you can clerk
they can clerk 	I can be clerking
you can be clerking
she can be clerking
we can be clerking
you can be clerking
they can be clerking	I can have clerked
you can have clerked
she can have clerked
we can have clerked
you can have clerked
they can have clerked	I can have been clerking
you can have been clerking
she can have been clerking
we can have been clerking
you can have been clerking
they can have been clerking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot clerk
you cannot clerk
she cannot clerk
we cannot clerk
you cannot clerk
they cannot clerk 	I cannot be clerking
you cannot be clerking
she cannot be clerking
we cannot be clerking
you cannot be clerking
they cannot be clerking	I cannot have clerked
you cannot have clerked
she cannot have clerked
we cannot have clerked
you cannot have clerked
they cannot have clerked	I cannot have been clerking
you cannot have been clerking
she cannot have been clerking
we cannot have been clerking
you cannot have been clerking
they cannot have been clerking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I clerk?
can you clerk?
can she clerk?
can we clerk?
can you clerk?
can they clerk? 	can I be clerking?
can you be clerking?
can she be clerking?
can we be clerking?
can you be clerking?
can they be clerking? 	can I have clerked?
can you have clerked?
can she have clerked?
can we have clerked?
can you have clerked?
can they have clerked? 	can I have been clerking?
can you have been clerking?
can she have been clerking?
can we have been clerking?
can you have been clerking?
can they have been clerking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not clerk?
can you not clerk?
can she not clerk?
can we not clerk?
can you not clerk?
can they not clerk? 	can I not be clerking?
can you not be clerking?
can she not be clerking?
can we not be clerking?
can you not be clerking?
can they not be clerking? 	can I not have clerked?
can you not have clerked?
can she not have clerked?
can we not have clerked?
can you not have clerked?
can they not have clerked? 	can I not have been clerking?
can you not have been clerking?
can she not have been clerking?
can we not have been clerking?
can you not have been clerking?
can they not have been clerking?