could tug
Regular verb: tug - tugged- tugged

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could tug
you could tug
she could tug
we could tug
you could tug
they could tug 	I could be tugging
you could be tugging
she could be tugging
we could be tugging
you could be tugging
they could be tugging	I could have tugged
you could have tugged
she could have tugged
we could have tugged
you could have tugged
they could have tugged	I could have been tugging
you could have been tugging
she could have been tugging
we could have been tugging
you could have been tugging
they could have been tugging	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't tug
you couldn't tug
she couldn't tug
we couldn't tug
you couldn't tug
they couldn't tug 	I couldn't be tugging
you couldn't be tugging
she couldn't be tugging
we couldn't be tugging
you couldn't be tugging
they couldn't be tugging	I couldn't have tugged
you couldn't have tugged
she couldn't have tugged
we couldn't have tugged
you couldn't have tugged
they couldn't have tugged	I couldn't have been tugging
you couldn't have been tugging
she couldn't have been tugging
we couldn't have been tugging
you couldn't have been tugging
they couldn't have been tugging	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I tug?
could you tug?
could she tug?
could we tug?
could you tug?
could they tug? 	could I be tugging?
could you be tugging?
could she be tugging?
could we be tugging?
could you be tugging?
could they be tugging? 	could I have tugged?
could you have tugged?
could she have tugged?
could we have tugged?
could you have tugged?
could they have tugged? 	could I have been tugging?
could you have been tugging?
could she have been tugging?
could we have been tugging?
could you have been tugging?
could they have been tugging? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I tug?
couldn't you tug?
couldn't she tug?
couldn't we tug?
couldn't you tug?
couldn't they tug? 	couldn't I be tugging?
couldn't you be tugging?
couldn't she be tugging?
couldn't we be tugging?
couldn't you be tugging?
couldn't they be tugging? 	couldn't I have tugged?
couldn't you have tugged?
couldn't she have tugged?
couldn't we have tugged?
couldn't you have tugged?
couldn't they have tugged? 	couldn't I have been tugging?
couldn't you have been tugging?
couldn't she have been tugging?
couldn't we have been tugging?
couldn't you have been tugging?
couldn't they have been tugging?