could tether
Regular verb: tether - tethered- tethered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could tether
you could tether
she could tether
we could tether
you could tether
they could tether 	I could be tethering
you could be tethering
she could be tethering
we could be tethering
you could be tethering
they could be tethering	I could have tethered
you could have tethered
she could have tethered
we could have tethered
you could have tethered
they could have tethered	I could have been tethering
you could have been tethering
she could have been tethering
we could have been tethering
you could have been tethering
they could have been tethering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not tether
you could not tether
she could not tether
we could not tether
you could not tether
they could not tether 	I could not be tethering
you could not be tethering
she could not be tethering
we could not be tethering
you could not be tethering
they could not be tethering	I could not have tethered
you could not have tethered
she could not have tethered
we could not have tethered
you could not have tethered
they could not have tethered	I could not have been tethering
you could not have been tethering
she could not have been tethering
we could not have been tethering
you could not have been tethering
they could not have been tethering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I tether?
could you tether?
could she tether?
could we tether?
could you tether?
could they tether? 	could I be tethering?
could you be tethering?
could she be tethering?
could we be tethering?
could you be tethering?
could they be tethering? 	could I have tethered?
could you have tethered?
could she have tethered?
could we have tethered?
could you have tethered?
could they have tethered? 	could I have been tethering?
could you have been tethering?
could she have been tethering?
could we have been tethering?
could you have been tethering?
could they have been tethering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not tether?
could you not tether?
could she not tether?
could we not tether?
could you not tether?
could they not tether? 	could I not be tethering?
could you not be tethering?
could she not be tethering?
could we not be tethering?
could you not be tethering?
could they not be tethering? 	could I not have tethered?
could you not have tethered?
could she not have tethered?
could we not have tethered?
could you not have tethered?
could they not have tethered? 	could I not have been tethering?
could you not have been tethering?
could she not have been tethering?
could we not have been tethering?
could you not have been tethering?
could they not have been tethering?