could yuck
Regular verb: yuck - yucked- yucked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could yuck
you could yuck
he could yuck
we could yuck
you could yuck
they could yuck 	I could be yucking
you could be yucking
he could be yucking
we could be yucking
you could be yucking
they could be yucking	I could have yucked
you could have yucked
he could have yucked
we could have yucked
you could have yucked
they could have yucked	I could have been yucking
you could have been yucking
he could have been yucking
we could have been yucking
you could have been yucking
they could have been yucking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't yuck
you couldn't yuck
he couldn't yuck
we couldn't yuck
you couldn't yuck
they couldn't yuck 	I couldn't be yucking
you couldn't be yucking
he couldn't be yucking
we couldn't be yucking
you couldn't be yucking
they couldn't be yucking	I couldn't have yucked
you couldn't have yucked
he couldn't have yucked
we couldn't have yucked
you couldn't have yucked
they couldn't have yucked	I couldn't have been yucking
you couldn't have been yucking
he couldn't have been yucking
we couldn't have been yucking
you couldn't have been yucking
they couldn't have been yucking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I yuck?
could you yuck?
could he yuck?
could we yuck?
could you yuck?
could they yuck? 	could I be yucking?
could you be yucking?
could he be yucking?
could we be yucking?
could you be yucking?
could they be yucking? 	could I have yucked?
could you have yucked?
could he have yucked?
could we have yucked?
could you have yucked?
could they have yucked? 	could I have been yucking?
could you have been yucking?
could he have been yucking?
could we have been yucking?
could you have been yucking?
could they have been yucking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I yuck?
couldn't you yuck?
couldn't he yuck?
couldn't we yuck?
couldn't you yuck?
couldn't they yuck? 	couldn't I be yucking?
couldn't you be yucking?
couldn't he be yucking?
couldn't we be yucking?
couldn't you be yucking?
couldn't they be yucking? 	couldn't I have yucked?
couldn't you have yucked?
couldn't he have yucked?
couldn't we have yucked?
couldn't you have yucked?
couldn't they have yucked? 	couldn't I have been yucking?
couldn't you have been yucking?
couldn't he have been yucking?
couldn't we have been yucking?
couldn't you have been yucking?
couldn't they have been yucking?