English verb conjugation
COULD FLUTTER

Regular verb: flutter - fluttered - fluttered

Affirmation

Simple form	V-ing form
I could flutter you could flutter he could flutter we could flutter you could flutter they could flutter	I could be fluttering you could be fluttering he could be fluttering we could be fluttering you could be fluttering they could be fluttering
Perfect	V-ing perfect
I could have fluttered you could have fluttered he could have fluttered we could have fluttered you could have fluttered they could have fluttered	I could have been fluttering you could have been fluttering he could have been fluttering we could have been fluttering you could have been fluttering they could have been fluttering

Negation

Simple form	V-ing form
I could not flutter you could not flutter he could not flutter we could not flutter you could not flutter they could not flutter	I could not be fluttering you could not be fluttering he could not be fluttering we could not be fluttering you could not be fluttering they could not be fluttering
Perfect	V-ing perfect
I could not have fluttered you could not have fluttered he could not have fluttered we could not have fluttered you could not have fluttered they could not have fluttered	I could not have been fluttering you could not have been fluttering he could not have been fluttering we could not have been fluttering you could not have been fluttering they could not have been fluttering

Interrogative form

Simple form	V-ing form
could I flutter? could you flutter? could he flutter? could we flutter? could you flutter? could they flutter?	could I be fluttering? could you be fluttering? could he be fluttering? could we be fluttering? could you be fluttering? could they be fluttering?
Perfect	V-ing perfect
could I have fluttered? could you have fluttered? could he have fluttered? could we have fluttered? could you have fluttered? could they have fluttered?	could I have been fluttering? could you have been fluttering? could he have been fluttering? could we have been fluttering? could you have been fluttering? could they have been fluttering?

Interro-negative form

Simple form	V-ing form
could I not flutter? could you not flutter? could he not flutter? could we not flutter? could you not flutter? could they not flutter?	could I not be fluttering? could you not be fluttering? could he not be fluttering? could we not be fluttering? could you not be fluttering? could they not be fluttering?
Perfect	V-ing perfect
could I not have fluttered? could you not have fluttered? could he not have fluttered? could we not have fluttered? could you not have fluttered? could they not have fluttered?	could I not have been fluttering? could you not have been fluttering? could he not have been fluttering? could we not have been fluttering? could you not have been fluttering? could they not have been fluttering?