English verb conjugation
COULD ROIL

Regular verb: roil - roiled - roiled

Affirmation

Simple form	V-ing form
I could roil you could roil he could roil we could roil you could roil they could roil	I could be roiling you could be roiling he could be roiling we could be roiling you could be roiling they could be roiling
Perfect	V-ing perfect
I could have roiled you could have roiled he could have roiled we could have roiled you could have roiled they could have roiled	I could have been roiling you could have been roiling he could have been roiling we could have been roiling you could have been roiling they could have been roiling

Negation

Simple form	V-ing form
I could not roil you could not roil he could not roil we could not roil you could not roil they could not roil	I could not be roiling you could not be roiling he could not be roiling we could not be roiling you could not be roiling they could not be roiling
Perfect	V-ing perfect
I could not have roiled you could not have roiled he could not have roiled we could not have roiled you could not have roiled they could not have roiled	I could not have been roiling you could not have been roiling he could not have been roiling we could not have been roiling you could not have been roiling they could not have been roiling

Interrogative form

Simple form	V-ing form
could I roil? could you roil? could he roil? could we roil? could you roil? could they roil?	could I be roiling? could you be roiling? could he be roiling? could we be roiling? could you be roiling? could they be roiling?
Perfect	V-ing perfect
could I have roiled? could you have roiled? could he have roiled? could we have roiled? could you have roiled? could they have roiled?	could I have been roiling? could you have been roiling? could he have been roiling? could we have been roiling? could you have been roiling? could they have been roiling?

Interro-negative form

Simple form	V-ing form
could I not roil? could you not roil? could he not roil? could we not roil? could you not roil? could they not roil?	could I not be roiling? could you not be roiling? could he not be roiling? could we not be roiling? could you not be roiling? could they not be roiling?
Perfect	V-ing perfect
could I not have roiled? could you not have roiled? could he not have roiled? could we not have roiled? could you not have roiled? could they not have roiled?	could I not have been roiling? could you not have been roiling? could he not have been roiling? could we not have been roiling? could you not have been roiling? could they not have been roiling?