could tank
Regular verb: tank - tanked- tanked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could tank
you could tank
he could tank
we could tank
you could tank
they could tank 	I could be tanking
you could be tanking
he could be tanking
we could be tanking
you could be tanking
they could be tanking	I could have tanked
you could have tanked
he could have tanked
we could have tanked
you could have tanked
they could have tanked	I could have been tanking
you could have been tanking
he could have been tanking
we could have been tanking
you could have been tanking
they could have been tanking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't tank
you couldn't tank
he couldn't tank
we couldn't tank
you couldn't tank
they couldn't tank 	I couldn't be tanking
you couldn't be tanking
he couldn't be tanking
we couldn't be tanking
you couldn't be tanking
they couldn't be tanking	I couldn't have tanked
you couldn't have tanked
he couldn't have tanked
we couldn't have tanked
you couldn't have tanked
they couldn't have tanked	I couldn't have been tanking
you couldn't have been tanking
he couldn't have been tanking
we couldn't have been tanking
you couldn't have been tanking
they couldn't have been tanking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I tank?
could you tank?
could he tank?
could we tank?
could you tank?
could they tank? 	could I be tanking?
could you be tanking?
could he be tanking?
could we be tanking?
could you be tanking?
could they be tanking? 	could I have tanked?
could you have tanked?
could he have tanked?
could we have tanked?
could you have tanked?
could they have tanked? 	could I have been tanking?
could you have been tanking?
could he have been tanking?
could we have been tanking?
could you have been tanking?
could they have been tanking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I tank?
couldn't you tank?
couldn't he tank?
couldn't we tank?
couldn't you tank?
couldn't they tank? 	couldn't I be tanking?
couldn't you be tanking?
couldn't he be tanking?
couldn't we be tanking?
couldn't you be tanking?
couldn't they be tanking? 	couldn't I have tanked?
couldn't you have tanked?
couldn't he have tanked?
couldn't we have tanked?
couldn't you have tanked?
couldn't they have tanked? 	couldn't I have been tanking?
couldn't you have been tanking?
couldn't he have been tanking?
couldn't we have been tanking?
couldn't you have been tanking?
couldn't they have been tanking?