I can quicken you can quicken he can quicken we can quicken you can quicken they can quicken
V-ing form
I can be quickening you can be quickening he can be quickening we can be quickening you can be quickening they can be quickening
Perfect
I can have quickened you can have quickened he can have quickened we can have quickened you can have quickened they can have quickened
V-ing perfect
I can have been quickening you can have been quickening he can have been quickening we can have been quickening you can have been quickening they can have been quickening
Negation
Simple form
I can't quicken you can't quicken he can't quicken we can't quicken you can't quicken they can't quicken
V-ing form
I can't be quickening you can't be quickening he can't be quickening we can't be quickening you can't be quickening they can't be quickening
Perfect
I can't have quickened you can't have quickened he can't have quickened we can't have quickened you can't have quickened they can't have quickened
V-ing perfect
I can't have been quickening you can't have been quickening he can't have been quickening we can't have been quickening you can't have been quickening they can't have been quickening
Interrogative form
Simple form
can I quicken? can you quicken? can he quicken? can we quicken? can you quicken? can they quicken?
V-ing form
can I be quickening? can you be quickening? can he be quickening? can we be quickening? can you be quickening? can they be quickening?
Perfect
can I have quickened? can you have quickened? can he have quickened? can we have quickened? can you have quickened? can they have quickened?
V-ing perfect
can I have been quickening? can you have been quickening? can he have been quickening? can we have been quickening? can you have been quickening? can they have been quickening?
Interro-negative form
Simple form
can't I quicken? can't you quicken? can't he quicken? can't we quicken? can't you quicken? can't they quicken?
V-ing form
can't I be quickening? can't you be quickening? can't he be quickening? can't we be quickening? can't you be quickening? can't they be quickening?
Perfect
can't I have quickened? can't you have quickened? can't he have quickened? can't we have quickened? can't you have quickened? can't they have quickened?
V-ing perfect
can't I have been quickening? can't you have been quickening? can't he have been quickening? can't we have been quickening? can't you have been quickening? can't they have been quickening?