English verb conjugation
COULD RETRAIN

Regular verb: retrain - retrained - retrained

Affirmation

Simple form	V-ing form
I could retrain you could retrain he could retrain we could retrain you could retrain they could retrain	I could be retraining you could be retraining he could be retraining we could be retraining you could be retraining they could be retraining
Perfect	V-ing perfect
I could have retrained you could have retrained he could have retrained we could have retrained you could have retrained they could have retrained	I could have been retraining you could have been retraining he could have been retraining we could have been retraining you could have been retraining they could have been retraining

Negation

Simple form	V-ing form
I could not retrain you could not retrain he could not retrain we could not retrain you could not retrain they could not retrain	I could not be retraining you could not be retraining he could not be retraining we could not be retraining you could not be retraining they could not be retraining
Perfect	V-ing perfect
I could not have retrained you could not have retrained he could not have retrained we could not have retrained you could not have retrained they could not have retrained	I could not have been retraining you could not have been retraining he could not have been retraining we could not have been retraining you could not have been retraining they could not have been retraining

Interrogative form

Simple form	V-ing form
could I retrain? could you retrain? could he retrain? could we retrain? could you retrain? could they retrain?	could I be retraining? could you be retraining? could he be retraining? could we be retraining? could you be retraining? could they be retraining?
Perfect	V-ing perfect
could I have retrained? could you have retrained? could he have retrained? could we have retrained? could you have retrained? could they have retrained?	could I have been retraining? could you have been retraining? could he have been retraining? could we have been retraining? could you have been retraining? could they have been retraining?

Interro-negative form

Simple form	V-ing form
could I not retrain? could you not retrain? could he not retrain? could we not retrain? could you not retrain? could they not retrain?	could I not be retraining? could you not be retraining? could he not be retraining? could we not be retraining? could you not be retraining? could they not be retraining?
Perfect	V-ing perfect
could I not have retrained? could you not have retrained? could he not have retrained? could we not have retrained? could you not have retrained? could they not have retrained?	could I not have been retraining? could you not have been retraining? could he not have been retraining? could we not have been retraining? could you not have been retraining? could they not have been retraining?