could untangle
Regular verb: untangle - untangled- untangled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could untangle
you could untangle
he could untangle
we could untangle
you could untangle
they could untangle 	I could be untangling
you could be untangling
he could be untangling
we could be untangling
you could be untangling
they could be untangling	I could have untangled
you could have untangled
he could have untangled
we could have untangled
you could have untangled
they could have untangled	I could have been untangling
you could have been untangling
he could have been untangling
we could have been untangling
you could have been untangling
they could have been untangling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not untangle
you could not untangle
he could not untangle
we could not untangle
you could not untangle
they could not untangle 	I could not be untangling
you could not be untangling
he could not be untangling
we could not be untangling
you could not be untangling
they could not be untangling	I could not have untangled
you could not have untangled
he could not have untangled
we could not have untangled
you could not have untangled
they could not have untangled	I could not have been untangling
you could not have been untangling
he could not have been untangling
we could not have been untangling
you could not have been untangling
they could not have been untangling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I untangle?
could you untangle?
could he untangle?
could we untangle?
could you untangle?
could they untangle? 	could I be untangling?
could you be untangling?
could he be untangling?
could we be untangling?
could you be untangling?
could they be untangling? 	could I have untangled?
could you have untangled?
could he have untangled?
could we have untangled?
could you have untangled?
could they have untangled? 	could I have been untangling?
could you have been untangling?
could he have been untangling?
could we have been untangling?
could you have been untangling?
could they have been untangling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not untangle?
could you not untangle?
could he not untangle?
could we not untangle?
could you not untangle?
could they not untangle? 	could I not be untangling?
could you not be untangling?
could he not be untangling?
could we not be untangling?
could you not be untangling?
could they not be untangling? 	could I not have untangled?
could you not have untangled?
could he not have untangled?
could we not have untangled?
could you not have untangled?
could they not have untangled? 	could I not have been untangling?
could you not have been untangling?
could he not have been untangling?
could we not have been untangling?
could you not have been untangling?
could they not have been untangling?