English verb conjugation
COULD TUN

Regular verb: tun - tuned - tuned

Affirmation

Simple form	V-ing form
I could tun you could tun he could tun we could tun you could tun they could tun	I could be tuning you could be tuning he could be tuning we could be tuning you could be tuning they could be tuning
Perfect	V-ing perfect
I could have tuned you could have tuned he 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 he 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
I couldn't tun you couldn't tun he couldn't tun we couldn't tun you couldn't tun they couldn't tun	I couldn't be tuning you couldn't be tuning he couldn't be tuning we couldn't be tuning you couldn't be tuning they couldn't be tuning
Perfect	V-ing perfect
I couldn't have tuned you couldn't have tuned he couldn't have tuned we couldn't have tuned you couldn't have tuned they couldn't have tuned	I couldn't have been tuning you couldn't have been tuning he couldn't have been tuning we couldn't have been tuning you couldn't have been tuning they couldn't have been tuning

Interrogative form

Simple form	V-ing form
could I tun? could you tun? could he tun? could we tun? could you tun? could they tun?	could I be tuning? could you be tuning? could he be tuning? could we be tuning? could you be tuning? could they be tuning?
Perfect	V-ing perfect
could I have tuned? could you have tuned? could he 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 he 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
couldn't I tun? couldn't you tun? couldn't he tun? couldn't we tun? couldn't you tun? couldn't they tun?	couldn't I be tuning? couldn't you be tuning? couldn't he be tuning? couldn't we be tuning? couldn't you be tuning? couldn't they be tuning?
Perfect	V-ing perfect
couldn't I have tuned? couldn't you have tuned? couldn't he have tuned? couldn't we have tuned? couldn't you have tuned? couldn't they have tuned?	couldn't I have been tuning? couldn't you have been tuning? couldn't he have been tuning? couldn't we have been tuning? couldn't you have been tuning? couldn't they have been tuning?