could clerk
Regular verb: clerk - clerked- clerked

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

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

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

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