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 couldn't roil you couldn't roil he couldn't roil we couldn't roil you couldn't roil they couldn't roil	I couldn't be roiling you couldn't be roiling he couldn't be roiling we couldn't be roiling you couldn't be roiling they couldn't be roiling
Perfect	V-ing perfect
I couldn't have roiled you couldn't have roiled he couldn't have roiled we couldn't have roiled you couldn't have roiled they couldn't have roiled	I couldn't have been roiling you couldn't have been roiling he couldn't have been roiling we couldn't have been roiling you couldn't have been roiling they couldn't 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
couldn't I roil? couldn't you roil? couldn't he roil? couldn't we roil? couldn't you roil? couldn't they roil?	couldn't I be roiling? couldn't you be roiling? couldn't he be roiling? couldn't we be roiling? couldn't you be roiling? couldn't they be roiling?
Perfect	V-ing perfect
couldn't I have roiled? couldn't you have roiled? couldn't he have roiled? couldn't we have roiled? couldn't you have roiled? couldn't they have roiled?	couldn't I have been roiling? couldn't you have been roiling? couldn't he have been roiling? couldn't we have been roiling? couldn't you have been roiling? couldn't they have been roiling?