English verb conjugation
COULD CONSTRAIN

Regular verb: constrain - constrained - constrained

Affirmation

Simple form	V-ing form
I could constrain you could constrain he could constrain we could constrain you could constrain they could constrain	I could be constraining you could be constraining he could be constraining we could be constraining you could be constraining they could be constraining
Perfect	V-ing perfect
I could have constrained you could have constrained he could have constrained we could have constrained you could have constrained they could have constrained	I could have been constraining you could have been constraining he could have been constraining we could have been constraining you could have been constraining they could have been constraining

Negation

Simple form	V-ing form
I couldn't constrain you couldn't constrain he couldn't constrain we couldn't constrain you couldn't constrain they couldn't constrain	I couldn't be constraining you couldn't be constraining he couldn't be constraining we couldn't be constraining you couldn't be constraining they couldn't be constraining
Perfect	V-ing perfect
I couldn't have constrained you couldn't have constrained he couldn't have constrained we couldn't have constrained you couldn't have constrained they couldn't have constrained	I couldn't have been constraining you couldn't have been constraining he couldn't have been constraining we couldn't have been constraining you couldn't have been constraining they couldn't have been constraining

Interrogative form

Simple form	V-ing form
could I constrain? could you constrain? could he constrain? could we constrain? could you constrain? could they constrain?	could I be constraining? could you be constraining? could he be constraining? could we be constraining? could you be constraining? could they be constraining?
Perfect	V-ing perfect
could I have constrained? could you have constrained? could he have constrained? could we have constrained? could you have constrained? could they have constrained?	could I have been constraining? could you have been constraining? could he have been constraining? could we have been constraining? could you have been constraining? could they have been constraining?

Interro-negative form

Simple form	V-ing form
couldn't I constrain? couldn't you constrain? couldn't he constrain? couldn't we constrain? couldn't you constrain? couldn't they constrain?	couldn't I be constraining? couldn't you be constraining? couldn't he be constraining? couldn't we be constraining? couldn't you be constraining? couldn't they be constraining?
Perfect	V-ing perfect
couldn't I have constrained? couldn't you have constrained? couldn't he have constrained? couldn't we have constrained? couldn't you have constrained? couldn't they have constrained?	couldn't I have been constraining? couldn't you have been constraining? couldn't he have been constraining? couldn't we have been constraining? couldn't you have been constraining? couldn't they have been constraining?