English verb conjugation
COULD CONVULSE

Regular verb: convulse - convulsed - convulsed

Affirmation

Simple form	V-ing form
I could convulse you could convulse she could convulse we could convulse you could convulse they could convulse	I could be convulsing you could be convulsing she 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 she 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 she 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 couldn't convulse you couldn't convulse she couldn't convulse we couldn't convulse you couldn't convulse they couldn't convulse	I couldn't be convulsing you couldn't be convulsing she couldn't be convulsing we couldn't be convulsing you couldn't be convulsing they couldn't be convulsing
Perfect	V-ing perfect
I couldn't have convulsed you couldn't have convulsed she couldn't have convulsed we couldn't have convulsed you couldn't have convulsed they couldn't have convulsed	I couldn't have been convulsing you couldn't have been convulsing she couldn't have been convulsing we couldn't have been convulsing you couldn't have been convulsing they couldn't have been convulsing

Interrogative form

Simple form	V-ing form
could I convulse? could you convulse? could she convulse? could we convulse? could you convulse? could they convulse?	could I be convulsing? could you be convulsing? could she 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 she 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 she 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
couldn't I convulse? couldn't you convulse? couldn't she convulse? couldn't we convulse? couldn't you convulse? couldn't they convulse?	couldn't I be convulsing? couldn't you be convulsing? couldn't she be convulsing? couldn't we be convulsing? couldn't you be convulsing? couldn't they be convulsing?
Perfect	V-ing perfect
couldn't I have convulsed? couldn't you have convulsed? couldn't she have convulsed? couldn't we have convulsed? couldn't you have convulsed? couldn't they have convulsed?	couldn't I have been convulsing? couldn't you have been convulsing? couldn't she have been convulsing? couldn't we have been convulsing? couldn't you have been convulsing? couldn't they have been convulsing?