could tun
Regular verb: tun - tuned- tuned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could tun
you could tun
she could tun
we could tun
you could tun
they could tun 	I could be tuning
you could be tuning
she could be tuning
we could be tuning
you could be tuning
they could be tuning	I could have tuned
you could have tuned
she could have tuned
we could have tuned
you could have tuned
they could have tuned	I could have been tuning
you could have been tuning
she could have been tuning
we could have been tuning
you could have been tuning
they could have been tuning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not tun
you could not tun
she could not tun
we could not tun
you could not tun
they could not tun 	I could not be tuning
you could not be tuning
she could not be tuning
we could not be tuning
you could not be tuning
they could not be tuning	I could not have tuned
you could not have tuned
she could not have tuned
we could not have tuned
you could not have tuned
they could not have tuned	I could not have been tuning
you could not have been tuning
she could not have been tuning
we could not have been tuning
you could not have been tuning
they could not have been tuning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I tun?
could you tun?
could she tun?
could we tun?
could you tun?
could they tun? 	could I be tuning?
could you be tuning?
could she be tuning?
could we be tuning?
could you be tuning?
could they be tuning? 	could I have tuned?
could you have tuned?
could she have tuned?
could we have tuned?
could you have tuned?
could they have tuned? 	could I have been tuning?
could you have been tuning?
could she have been tuning?
could we have been tuning?
could you have been tuning?
could they have been tuning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not tun?
could you not tun?
could she not tun?
could we not tun?
could you not tun?
could they not tun? 	could I not be tuning?
could you not be tuning?
could she not be tuning?
could we not be tuning?
could you not be tuning?
could they not be tuning? 	could I not have tuned?
could you not have tuned?
could she not have tuned?
could we not have tuned?
could you not have tuned?
could they not have tuned? 	could I not have been tuning?
could you not have been tuning?
could she not have been tuning?
could we not have been tuning?
could you not have been tuning?
could they not have been tuning?