English verb conjugation
COULD CAVERN

Regular verb: cavern - caverned - caverned

Affirmation

Simple form	V-ing form
I could cavern you could cavern she could cavern we could cavern you could cavern they could cavern	I could be caverning you could be caverning she could be caverning we could be caverning you could be caverning they could be caverning
Perfect	V-ing perfect
I could have caverned you could have caverned she could have caverned we could have caverned you could have caverned they could have caverned	I could have been caverning you could have been caverning she could have been caverning we could have been caverning you could have been caverning they could have been caverning

Negation

Simple form	V-ing form
I couldn't cavern you couldn't cavern she couldn't cavern we couldn't cavern you couldn't cavern they couldn't cavern	I couldn't be caverning you couldn't be caverning she couldn't be caverning we couldn't be caverning you couldn't be caverning they couldn't be caverning
Perfect	V-ing perfect
I couldn't have caverned you couldn't have caverned she couldn't have caverned we couldn't have caverned you couldn't have caverned they couldn't have caverned	I couldn't have been caverning you couldn't have been caverning she couldn't have been caverning we couldn't have been caverning you couldn't have been caverning they couldn't have been caverning

Interrogative form

Simple form	V-ing form
could I cavern? could you cavern? could she cavern? could we cavern? could you cavern? could they cavern?	could I be caverning? could you be caverning? could she be caverning? could we be caverning? could you be caverning? could they be caverning?
Perfect	V-ing perfect
could I have caverned? could you have caverned? could she have caverned? could we have caverned? could you have caverned? could they have caverned?	could I have been caverning? could you have been caverning? could she have been caverning? could we have been caverning? could you have been caverning? could they have been caverning?

Interro-negative form

Simple form	V-ing form
couldn't I cavern? couldn't you cavern? couldn't she cavern? couldn't we cavern? couldn't you cavern? couldn't they cavern?	couldn't I be caverning? couldn't you be caverning? couldn't she be caverning? couldn't we be caverning? couldn't you be caverning? couldn't they be caverning?
Perfect	V-ing perfect
couldn't I have caverned? couldn't you have caverned? couldn't she have caverned? couldn't we have caverned? couldn't you have caverned? couldn't they have caverned?	couldn't I have been caverning? couldn't you have been caverning? couldn't she have been caverning? couldn't we have been caverning? couldn't you have been caverning? couldn't they have been caverning?