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 could not sicken you could not sicken he could not sicken we could not sicken you could not sicken they could not sicken	I could not be sickening you could not be sickening he could not be sickening we could not be sickening you could not be sickening they could not be sickening
Perfect	V-ing perfect
I could not have sickened you could not have sickened he could not have sickened we could not have sickened you could not have sickened they could not have sickened	I could not have been sickening you could not have been sickening he could not have been sickening we could not have been sickening you could not have been sickening they could not 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
could I not sicken? could you not sicken? could he not sicken? could we not sicken? could you not sicken? could they not sicken?	could I not be sickening? could you not be sickening? could he not be sickening? could we not be sickening? could you not be sickening? could they not be sickening?
Perfect	V-ing perfect
could I not have sickened? could you not have sickened? could he not have sickened? could we not have sickened? could you not have sickened? could they not have sickened?	could I not have been sickening? could you not have been sickening? could he not have been sickening? could we not have been sickening? could you not have been sickening? could they not have been sickening?