English verb conjugation
COULD INTER

Regular verb: inter - interred - interred

Affirmation

Simple form	V-ing form
I could inter you could inter he could inter we could inter you could inter they could inter	I could be interring you could be interring he could be interring we could be interring you could be interring they could be interring
Perfect	V-ing perfect
I could have interred you could have interred he could have interred we could have interred you could have interred they could have interred	I could have been interring you could have been interring he could have been interring we could have been interring you could have been interring they could have been interring

Negation

Simple form	V-ing form
I couldn't inter you couldn't inter he couldn't inter we couldn't inter you couldn't inter they couldn't inter	I couldn't be interring you couldn't be interring he couldn't be interring we couldn't be interring you couldn't be interring they couldn't be interring
Perfect	V-ing perfect
I couldn't have interred you couldn't have interred he couldn't have interred we couldn't have interred you couldn't have interred they couldn't have interred	I couldn't have been interring you couldn't have been interring he couldn't have been interring we couldn't have been interring you couldn't have been interring they couldn't have been interring

Interrogative form

Simple form	V-ing form
could I inter? could you inter? could he inter? could we inter? could you inter? could they inter?	could I be interring? could you be interring? could he be interring? could we be interring? could you be interring? could they be interring?
Perfect	V-ing perfect
could I have interred? could you have interred? could he have interred? could we have interred? could you have interred? could they have interred?	could I have been interring? could you have been interring? could he have been interring? could we have been interring? could you have been interring? could they have been interring?

Interro-negative form

Simple form	V-ing form
couldn't I inter? couldn't you inter? couldn't he inter? couldn't we inter? couldn't you inter? couldn't they inter?	couldn't I be interring? couldn't you be interring? couldn't he be interring? couldn't we be interring? couldn't you be interring? couldn't they be interring?
Perfect	V-ing perfect
couldn't I have interred? couldn't you have interred? couldn't he have interred? couldn't we have interred? couldn't you have interred? couldn't they have interred?	couldn't I have been interring? couldn't you have been interring? couldn't he have been interring? couldn't we have been interring? couldn't you have been interring? couldn't they have been interring?