English verb conjugation
COULD SICKEN

Regular verb: sicken - sickened - sickened

Affirmation

Simple form	V-ing form
I could sicken you could sicken he could sicken we could sicken you could sicken they could sicken	I could be sickening you could be sickening he could be sickening we could be sickening you could be sickening they could be sickening
Perfect	V-ing perfect
I could have sickened you could have sickened he could have sickened we could have sickened you could have sickened they could have sickened	I could have been sickening you could have been sickening he could have been sickening we could have been sickening you could have been sickening they could have been sickening

Negation

Simple form	V-ing form
I couldn't sicken you couldn't sicken he couldn't sicken we couldn't sicken you couldn't sicken they couldn't sicken	I couldn't be sickening you couldn't be sickening he couldn't be sickening we couldn't be sickening you couldn't be sickening they couldn't be sickening
Perfect	V-ing perfect
I couldn't have sickened you couldn't have sickened he couldn't have sickened we couldn't have sickened you couldn't have sickened they couldn't have sickened	I couldn't have been sickening you couldn't have been sickening he couldn't have been sickening we couldn't have been sickening you couldn't have been sickening they couldn't have been sickening

Interrogative form

Simple form	V-ing form
could I sicken? could you sicken? could he sicken? could we sicken? could you sicken? could they sicken?	could I be sickening? could you be sickening? could he be sickening? could we be sickening? could you be sickening? could they be sickening?
Perfect	V-ing perfect
could I have sickened? could you have sickened? could he have sickened? could we have sickened? could you have sickened? could they have sickened?	could I have been sickening? could you have been sickening? could he have been sickening? could we have been sickening? could you have been sickening? could they have been sickening?

Interro-negative form

Simple form	V-ing form
couldn't I sicken? couldn't you sicken? couldn't he sicken? couldn't we sicken? couldn't you sicken? couldn't they sicken?	couldn't I be sickening? couldn't you be sickening? couldn't he be sickening? couldn't we be sickening? couldn't you be sickening? couldn't they be sickening?
Perfect	V-ing perfect
couldn't I have sickened? couldn't you have sickened? couldn't he have sickened? couldn't we have sickened? couldn't you have sickened? couldn't they have sickened?	couldn't I have been sickening? couldn't you have been sickening? couldn't he have been sickening? couldn't we have been sickening? couldn't you have been sickening? couldn't they have been sickening?