English verb conjugation
COULD RETUNE

Regular verb: retune - retuned - retuned

Affirmation

Simple form	V-ing form
I could retune you could retune he could retune we could retune you could retune they could retune	I could be retuning you could be retuning he could be retuning we could be retuning you could be retuning they could be retuning
Perfect	V-ing perfect
I could have retuned you could have retuned he could have retuned we could have retuned you could have retuned they could have retuned	I could have been retuning you could have been retuning he could have been retuning we could have been retuning you could have been retuning they could have been retuning

Negation

Simple form	V-ing form
I couldn't retune you couldn't retune he couldn't retune we couldn't retune you couldn't retune they couldn't retune	I couldn't be retuning you couldn't be retuning he couldn't be retuning we couldn't be retuning you couldn't be retuning they couldn't be retuning
Perfect	V-ing perfect
I couldn't have retuned you couldn't have retuned he couldn't have retuned we couldn't have retuned you couldn't have retuned they couldn't have retuned	I couldn't have been retuning you couldn't have been retuning he couldn't have been retuning we couldn't have been retuning you couldn't have been retuning they couldn't have been retuning

Interrogative form

Simple form	V-ing form
could I retune? could you retune? could he retune? could we retune? could you retune? could they retune?	could I be retuning? could you be retuning? could he be retuning? could we be retuning? could you be retuning? could they be retuning?
Perfect	V-ing perfect
could I have retuned? could you have retuned? could he have retuned? could we have retuned? could you have retuned? could they have retuned?	could I have been retuning? could you have been retuning? could he have been retuning? could we have been retuning? could you have been retuning? could they have been retuning?

Interro-negative form

Simple form	V-ing form
couldn't I retune? couldn't you retune? couldn't he retune? couldn't we retune? couldn't you retune? couldn't they retune?	couldn't I be retuning? couldn't you be retuning? couldn't he be retuning? couldn't we be retuning? couldn't you be retuning? couldn't they be retuning?
Perfect	V-ing perfect
couldn't I have retuned? couldn't you have retuned? couldn't he have retuned? couldn't we have retuned? couldn't you have retuned? couldn't they have retuned?	couldn't I have been retuning? couldn't you have been retuning? couldn't he have been retuning? couldn't we have been retuning? couldn't you have been retuning? couldn't they have been retuning?