could yuk
Regular verb: yuk - yuked- yuked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could yuk
you could yuk
he could yuk
we could yuk
you could yuk
they could yuk 	I could be yuking
you could be yuking
he could be yuking
we could be yuking
you could be yuking
they could be yuking	I could have yuked
you could have yuked
he could have yuked
we could have yuked
you could have yuked
they could have yuked	I could have been yuking
you could have been yuking
he could have been yuking
we could have been yuking
you could have been yuking
they could have been yuking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not yuk
you could not yuk
he could not yuk
we could not yuk
you could not yuk
they could not yuk 	I could not be yuking
you could not be yuking
he could not be yuking
we could not be yuking
you could not be yuking
they could not be yuking	I could not have yuked
you could not have yuked
he could not have yuked
we could not have yuked
you could not have yuked
they could not have yuked	I could not have been yuking
you could not have been yuking
he could not have been yuking
we could not have been yuking
you could not have been yuking
they could not have been yuking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I yuk?
could you yuk?
could he yuk?
could we yuk?
could you yuk?
could they yuk? 	could I be yuking?
could you be yuking?
could he be yuking?
could we be yuking?
could you be yuking?
could they be yuking? 	could I have yuked?
could you have yuked?
could he have yuked?
could we have yuked?
could you have yuked?
could they have yuked? 	could I have been yuking?
could you have been yuking?
could he have been yuking?
could we have been yuking?
could you have been yuking?
could they have been yuking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not yuk?
could you not yuk?
could he not yuk?
could we not yuk?
could you not yuk?
could they not yuk? 	could I not be yuking?
could you not be yuking?
could he not be yuking?
could we not be yuking?
could you not be yuking?
could they not be yuking? 	could I not have yuked?
could you not have yuked?
could he not have yuked?
could we not have yuked?
could you not have yuked?
could they not have yuked? 	could I not have been yuking?
could you not have been yuking?
could he not have been yuking?
could we not have been yuking?
could you not have been yuking?
could they not have been yuking?