English verb conjugation
COULD QUICKEN

Regular verb: quicken - quickened - quickened

Affirmation

Simple form	V-ing form
I could quicken you could quicken he could quicken we could quicken you could quicken they could quicken	I could be quickening you could be quickening he could be quickening we could be quickening you could be quickening they could be quickening
Perfect	V-ing perfect
I could have quickened you could have quickened he could have quickened we could have quickened you could have quickened they could have quickened	I could have been quickening you could have been quickening he could have been quickening we could have been quickening you could have been quickening they could have been quickening

Negation

Simple form	V-ing form
I couldn't quicken you couldn't quicken he couldn't quicken we couldn't quicken you couldn't quicken they couldn't quicken	I couldn't be quickening you couldn't be quickening he couldn't be quickening we couldn't be quickening you couldn't be quickening they couldn't be quickening
Perfect	V-ing perfect
I couldn't have quickened you couldn't have quickened he couldn't have quickened we couldn't have quickened you couldn't have quickened they couldn't have quickened	I couldn't have been quickening you couldn't have been quickening he couldn't have been quickening we couldn't have been quickening you couldn't have been quickening they couldn't have been quickening

Interrogative form

Simple form	V-ing form
could I quicken? could you quicken? could he quicken? could we quicken? could you quicken? could they quicken?	could I be quickening? could you be quickening? could he be quickening? could we be quickening? could you be quickening? could they be quickening?
Perfect	V-ing perfect
could I have quickened? could you have quickened? could he have quickened? could we have quickened? could you have quickened? could they have quickened?	could I have been quickening? could you have been quickening? could he have been quickening? could we have been quickening? could you have been quickening? could they have been quickening?

Interro-negative form

Simple form	V-ing form
couldn't I quicken? couldn't you quicken? couldn't he quicken? couldn't we quicken? couldn't you quicken? couldn't they quicken?	couldn't I be quickening? couldn't you be quickening? couldn't he be quickening? couldn't we be quickening? couldn't you be quickening? couldn't they be quickening?
Perfect	V-ing perfect
couldn't I have quickened? couldn't you have quickened? couldn't he have quickened? couldn't we have quickened? couldn't you have quickened? couldn't they have quickened?	couldn't I have been quickening? couldn't you have been quickening? couldn't he have been quickening? couldn't we have been quickening? couldn't you have been quickening? couldn't they have been quickening?