English verb conjugation
COULD PREALTER

Regular verb: prealter - prealtered - prealtered

Affirmation

Simple form	V-ing form
I could prealter you could prealter he could prealter we could prealter you could prealter they could prealter	I could be prealtering you could be prealtering he could be prealtering we could be prealtering you could be prealtering they could be prealtering
Perfect	V-ing perfect
I could have prealtered you could have prealtered he could have prealtered we could have prealtered you could have prealtered they could have prealtered	I could have been prealtering you could have been prealtering he could have been prealtering we could have been prealtering you could have been prealtering they could have been prealtering

Negation

Simple form	V-ing form
I couldn't prealter you couldn't prealter he couldn't prealter we couldn't prealter you couldn't prealter they couldn't prealter	I couldn't be prealtering you couldn't be prealtering he couldn't be prealtering we couldn't be prealtering you couldn't be prealtering they couldn't be prealtering
Perfect	V-ing perfect
I couldn't have prealtered you couldn't have prealtered he couldn't have prealtered we couldn't have prealtered you couldn't have prealtered they couldn't have prealtered	I couldn't have been prealtering you couldn't have been prealtering he couldn't have been prealtering we couldn't have been prealtering you couldn't have been prealtering they couldn't have been prealtering

Interrogative form

Simple form	V-ing form
could I prealter? could you prealter? could he prealter? could we prealter? could you prealter? could they prealter?	could I be prealtering? could you be prealtering? could he be prealtering? could we be prealtering? could you be prealtering? could they be prealtering?
Perfect	V-ing perfect
could I have prealtered? could you have prealtered? could he have prealtered? could we have prealtered? could you have prealtered? could they have prealtered?	could I have been prealtering? could you have been prealtering? could he have been prealtering? could we have been prealtering? could you have been prealtering? could they have been prealtering?

Interro-negative form

Simple form	V-ing form
couldn't I prealter? couldn't you prealter? couldn't he prealter? couldn't we prealter? couldn't you prealter? couldn't they prealter?	couldn't I be prealtering? couldn't you be prealtering? couldn't he be prealtering? couldn't we be prealtering? couldn't you be prealtering? couldn't they be prealtering?
Perfect	V-ing perfect
couldn't I have prealtered? couldn't you have prealtered? couldn't he have prealtered? couldn't we have prealtered? couldn't you have prealtered? couldn't they have prealtered?	couldn't I have been prealtering? couldn't you have been prealtering? couldn't he have been prealtering? couldn't we have been prealtering? couldn't you have been prealtering? couldn't they have been prealtering?