English verb conjugation
COULD IMPAIR

Regular verb: impair - impaired - impaired

Affirmation

Simple form	V-ing form
I could impair you could impair he could impair we could impair you could impair they could impair	I could be impairing you could be impairing he could be impairing we could be impairing you could be impairing they could be impairing
Perfect	V-ing perfect
I could have impaired you could have impaired he could have impaired we could have impaired you could have impaired they could have impaired	I could have been impairing you could have been impairing he could have been impairing we could have been impairing you could have been impairing they could have been impairing

Negation

Simple form	V-ing form
I could not impair you could not impair he could not impair we could not impair you could not impair they could not impair	I could not be impairing you could not be impairing he could not be impairing we could not be impairing you could not be impairing they could not be impairing
Perfect	V-ing perfect
I could not have impaired you could not have impaired he could not have impaired we could not have impaired you could not have impaired they could not have impaired	I could not have been impairing you could not have been impairing he could not have been impairing we could not have been impairing you could not have been impairing they could not have been impairing

Interrogative form

Simple form	V-ing form
could I impair? could you impair? could he impair? could we impair? could you impair? could they impair?	could I be impairing? could you be impairing? could he be impairing? could we be impairing? could you be impairing? could they be impairing?
Perfect	V-ing perfect
could I have impaired? could you have impaired? could he have impaired? could we have impaired? could you have impaired? could they have impaired?	could I have been impairing? could you have been impairing? could he have been impairing? could we have been impairing? could you have been impairing? could they have been impairing?

Interro-negative form

Simple form	V-ing form
could I not impair? could you not impair? could he not impair? could we not impair? could you not impair? could they not impair?	could I not be impairing? could you not be impairing? could he not be impairing? could we not be impairing? could you not be impairing? could they not be impairing?
Perfect	V-ing perfect
could I not have impaired? could you not have impaired? could he not have impaired? could we not have impaired? could you not have impaired? could they not have impaired?	could I not have been impairing? could you not have been impairing? could he not have been impairing? could we not have been impairing? could you not have been impairing? could they not have been impairing?