English verb conjugation
COULD PREHARDEN

Regular verb: preharden - prehardened - prehardened

Affirmation

Simple form	V-ing form
I could preharden you could preharden he could preharden we could preharden you could preharden they could preharden	I could be prehardening you could be prehardening he could be prehardening we could be prehardening you could be prehardening they could be prehardening
Perfect	V-ing perfect
I could have prehardened you could have prehardened he could have prehardened we could have prehardened you could have prehardened they could have prehardened	I could have been prehardening you could have been prehardening he could have been prehardening we could have been prehardening you could have been prehardening they could have been prehardening

Negation

Simple form	V-ing form
I couldn't preharden you couldn't preharden he couldn't preharden we couldn't preharden you couldn't preharden they couldn't preharden	I couldn't be prehardening you couldn't be prehardening he couldn't be prehardening we couldn't be prehardening you couldn't be prehardening they couldn't be prehardening
Perfect	V-ing perfect
I couldn't have prehardened you couldn't have prehardened he couldn't have prehardened we couldn't have prehardened you couldn't have prehardened they couldn't have prehardened	I couldn't have been prehardening you couldn't have been prehardening he couldn't have been prehardening we couldn't have been prehardening you couldn't have been prehardening they couldn't have been prehardening

Interrogative form

Simple form	V-ing form
could I preharden? could you preharden? could he preharden? could we preharden? could you preharden? could they preharden?	could I be prehardening? could you be prehardening? could he be prehardening? could we be prehardening? could you be prehardening? could they be prehardening?
Perfect	V-ing perfect
could I have prehardened? could you have prehardened? could he have prehardened? could we have prehardened? could you have prehardened? could they have prehardened?	could I have been prehardening? could you have been prehardening? could he have been prehardening? could we have been prehardening? could you have been prehardening? could they have been prehardening?

Interro-negative form

Simple form	V-ing form
couldn't I preharden? couldn't you preharden? couldn't he preharden? couldn't we preharden? couldn't you preharden? couldn't they preharden?	couldn't I be prehardening? couldn't you be prehardening? couldn't he be prehardening? couldn't we be prehardening? couldn't you be prehardening? couldn't they be prehardening?
Perfect	V-ing perfect
couldn't I have prehardened? couldn't you have prehardened? couldn't he have prehardened? couldn't we have prehardened? couldn't you have prehardened? couldn't they have prehardened?	couldn't I have been prehardening? couldn't you have been prehardening? couldn't he have been prehardening? couldn't we have been prehardening? couldn't you have been prehardening? couldn't they have been prehardening?