English verb conjugation
COULD NIGGLE

Regular verb: niggle - niggled - niggled

Affirmation

Simple form	V-ing form
I could niggle you could niggle he could niggle we could niggle you could niggle they could niggle	I could be niggling you could be niggling he could be niggling we could be niggling you could be niggling they could be niggling
Perfect	V-ing perfect
I could have niggled you could have niggled he could have niggled we could have niggled you could have niggled they could have niggled	I could have been niggling you could have been niggling he could have been niggling we could have been niggling you could have been niggling they could have been niggling

Negation

Simple form	V-ing form
I could not niggle you could not niggle he could not niggle we could not niggle you could not niggle they could not niggle	I could not be niggling you could not be niggling he could not be niggling we could not be niggling you could not be niggling they could not be niggling
Perfect	V-ing perfect
I could not have niggled you could not have niggled he could not have niggled we could not have niggled you could not have niggled they could not have niggled	I could not have been niggling you could not have been niggling he could not have been niggling we could not have been niggling you could not have been niggling they could not have been niggling

Interrogative form

Simple form	V-ing form
could I niggle? could you niggle? could he niggle? could we niggle? could you niggle? could they niggle?	could I be niggling? could you be niggling? could he be niggling? could we be niggling? could you be niggling? could they be niggling?
Perfect	V-ing perfect
could I have niggled? could you have niggled? could he have niggled? could we have niggled? could you have niggled? could they have niggled?	could I have been niggling? could you have been niggling? could he have been niggling? could we have been niggling? could you have been niggling? could they have been niggling?

Interro-negative form

Simple form	V-ing form
could I not niggle? could you not niggle? could he not niggle? could we not niggle? could you not niggle? could they not niggle?	could I not be niggling? could you not be niggling? could he not be niggling? could we not be niggling? could you not be niggling? could they not be niggling?
Perfect	V-ing perfect
could I not have niggled? could you not have niggled? could he not have niggled? could we not have niggled? could you not have niggled? could they not have niggled?	could I not have been niggling? could you not have been niggling? could he not have been niggling? could we not have been niggling? could you not have been niggling? could they not have been niggling?