English verb conjugation
COULD RADIO

Regular verb: radio - radioed - radioed

Affirmation

Simple form	V-ing form
I could radio you could radio he could radio we could radio you could radio they could radio	I could be radioing you could be radioing he could be radioing we could be radioing you could be radioing they could be radioing
Perfect	V-ing perfect
I could have radioed you could have radioed he could have radioed we could have radioed you could have radioed they could have radioed	I could have been radioing you could have been radioing he could have been radioing we could have been radioing you could have been radioing they could have been radioing

Negation

Simple form	V-ing form
I couldn't radio you couldn't radio he couldn't radio we couldn't radio you couldn't radio they couldn't radio	I couldn't be radioing you couldn't be radioing he couldn't be radioing we couldn't be radioing you couldn't be radioing they couldn't be radioing
Perfect	V-ing perfect
I couldn't have radioed you couldn't have radioed he couldn't have radioed we couldn't have radioed you couldn't have radioed they couldn't have radioed	I couldn't have been radioing you couldn't have been radioing he couldn't have been radioing we couldn't have been radioing you couldn't have been radioing they couldn't have been radioing

Interrogative form

Simple form	V-ing form
could I radio? could you radio? could he radio? could we radio? could you radio? could they radio?	could I be radioing? could you be radioing? could he be radioing? could we be radioing? could you be radioing? could they be radioing?
Perfect	V-ing perfect
could I have radioed? could you have radioed? could he have radioed? could we have radioed? could you have radioed? could they have radioed?	could I have been radioing? could you have been radioing? could he have been radioing? could we have been radioing? could you have been radioing? could they have been radioing?

Interro-negative form

Simple form	V-ing form
couldn't I radio? couldn't you radio? couldn't he radio? couldn't we radio? couldn't you radio? couldn't they radio?	couldn't I be radioing? couldn't you be radioing? couldn't he be radioing? couldn't we be radioing? couldn't you be radioing? couldn't they be radioing?
Perfect	V-ing perfect
couldn't I have radioed? couldn't you have radioed? couldn't he have radioed? couldn't we have radioed? couldn't you have radioed? couldn't they have radioed?	couldn't I have been radioing? couldn't you have been radioing? couldn't he have been radioing? couldn't we have been radioing? couldn't you have been radioing? couldn't they have been radioing?