English verb conjugation
COULD CONVULSE

Regular verb: convulse - convulsed - convulsed

Affirmation

Simple form	V-ing form
I could convulse you could convulse he could convulse we could convulse you could convulse they could convulse	I could be convulsing you could be convulsing he could be convulsing we could be convulsing you could be convulsing they could be convulsing
Perfect	V-ing perfect
I could have convulsed you could have convulsed he could have convulsed we could have convulsed you could have convulsed they could have convulsed	I could have been convulsing you could have been convulsing he could have been convulsing we could have been convulsing you could have been convulsing they could have been convulsing

Negation

Simple form	V-ing form
I could not convulse you could not convulse he could not convulse we could not convulse you could not convulse they could not convulse	I could not be convulsing you could not be convulsing he could not be convulsing we could not be convulsing you could not be convulsing they could not be convulsing
Perfect	V-ing perfect
I could not have convulsed you could not have convulsed he could not have convulsed we could not have convulsed you could not have convulsed they could not have convulsed	I could not have been convulsing you could not have been convulsing he could not have been convulsing we could not have been convulsing you could not have been convulsing they could not have been convulsing

Interrogative form

Simple form	V-ing form
could I convulse? could you convulse? could he convulse? could we convulse? could you convulse? could they convulse?	could I be convulsing? could you be convulsing? could he be convulsing? could we be convulsing? could you be convulsing? could they be convulsing?
Perfect	V-ing perfect
could I have convulsed? could you have convulsed? could he have convulsed? could we have convulsed? could you have convulsed? could they have convulsed?	could I have been convulsing? could you have been convulsing? could he have been convulsing? could we have been convulsing? could you have been convulsing? could they have been convulsing?

Interro-negative form

Simple form	V-ing form
could I not convulse? could you not convulse? could he not convulse? could we not convulse? could you not convulse? could they not convulse?	could I not be convulsing? could you not be convulsing? could he not be convulsing? could we not be convulsing? could you not be convulsing? could they not be convulsing?
Perfect	V-ing perfect
could I not have convulsed? could you not have convulsed? could he not have convulsed? could we not have convulsed? could you not have convulsed? could they not have convulsed?	could I not have been convulsing? could you not have been convulsing? could he not have been convulsing? could we not have been convulsing? could you not have been convulsing? could they not have been convulsing?