English verb conjugation
COULD OVERWINTER

Regular verb: overwinter - overwintered - overwintered

Affirmation

Simple form	V-ing form
I could overwinter you could overwinter he could overwinter we could overwinter you could overwinter they could overwinter	I could be overwintering you could be overwintering he could be overwintering we could be overwintering you could be overwintering they could be overwintering
Perfect	V-ing perfect
I could have overwintered you could have overwintered he could have overwintered we could have overwintered you could have overwintered they could have overwintered	I could have been overwintering you could have been overwintering he could have been overwintering we could have been overwintering you could have been overwintering they could have been overwintering

Negation

Simple form	V-ing form
I couldn't overwinter you couldn't overwinter he couldn't overwinter we couldn't overwinter you couldn't overwinter they couldn't overwinter	I couldn't be overwintering you couldn't be overwintering he couldn't be overwintering we couldn't be overwintering you couldn't be overwintering they couldn't be overwintering
Perfect	V-ing perfect
I couldn't have overwintered you couldn't have overwintered he couldn't have overwintered we couldn't have overwintered you couldn't have overwintered they couldn't have overwintered	I couldn't have been overwintering you couldn't have been overwintering he couldn't have been overwintering we couldn't have been overwintering you couldn't have been overwintering they couldn't have been overwintering

Interrogative form

Simple form	V-ing form
could I overwinter? could you overwinter? could he overwinter? could we overwinter? could you overwinter? could they overwinter?	could I be overwintering? could you be overwintering? could he be overwintering? could we be overwintering? could you be overwintering? could they be overwintering?
Perfect	V-ing perfect
could I have overwintered? could you have overwintered? could he have overwintered? could we have overwintered? could you have overwintered? could they have overwintered?	could I have been overwintering? could you have been overwintering? could he have been overwintering? could we have been overwintering? could you have been overwintering? could they have been overwintering?

Interro-negative form

Simple form	V-ing form
couldn't I overwinter? couldn't you overwinter? couldn't he overwinter? couldn't we overwinter? couldn't you overwinter? couldn't they overwinter?	couldn't I be overwintering? couldn't you be overwintering? couldn't he be overwintering? couldn't we be overwintering? couldn't you be overwintering? couldn't they be overwintering?
Perfect	V-ing perfect
couldn't I have overwintered? couldn't you have overwintered? couldn't he have overwintered? couldn't we have overwintered? couldn't you have overwintered? couldn't they have overwintered?	couldn't I have been overwintering? couldn't you have been overwintering? couldn't he have been overwintering? couldn't we have been overwintering? couldn't you have been overwintering? couldn't they have been overwintering?