English verb conjugation
SHOULD RETAIN

Regular verb: retain - retained - retained

Affirmation

Simple form	V-ing form
I'd retain you'd retain he'd retain we'd retain you'd retain they'd retain	I'd be retaining you'd be retaining he'd be retaining we'd be retaining you'd be retaining they'd be retaining
Perfect	V-ing perfect
I should've retained you should've retained he should've retained we should've retained you should've retained they should've retained	I should've been retaining you should've been retaining he should've been retaining we should've been retaining you should've been retaining they should've been retaining

Negation

Simple form	V-ing form
I shouldn't retain you shouldn't retain he shouldn't retain we shouldn't retain you shouldn't retain they shouldn't retain	I shouldn't be retaining you shouldn't be retaining he shouldn't be retaining we shouldn't be retaining you shouldn't be retaining they shouldn't be retaining
Perfect	V-ing perfect
I shouldn't have retained you shouldn't have retained he shouldn't have retained we shouldn't have retained you shouldn't have retained they shouldn't have retained	I shouldn't have been retaining you shouldn't have been retaining he shouldn't have been retaining we shouldn't have been retaining you shouldn't have been retaining they shouldn't have been retaining

Interrogative form

Simple form	V-ing form
should I retain? should you retain? should he retain? should we retain? should you retain? should they retain?	should I be retaining? should you be retaining? should he be retaining? should we be retaining? should you be retaining? should they be retaining?
Perfect	V-ing perfect
should I have retained? should you have retained? should he have retained? should we have retained? should you have retained? should they have retained?	should I have been retaining? should you have been retaining? should he have been retaining? should we have been retaining? should you have been retaining? should they have been retaining?

Interro-negative form

Simple form	V-ing form
shouldn't I retain? shouldn't you retain? shouldn't he retain? shouldn't we retain? shouldn't you retain? shouldn't they retain?	shouldn't I be retaining? shouldn't you be retaining? shouldn't he be retaining? shouldn't we be retaining? shouldn't you be retaining? shouldn't they be retaining?
Perfect	V-ing perfect
shouldn't I have retained? shouldn't you have retained? shouldn't he have retained? shouldn't we have retained? shouldn't you have retained? shouldn't they have retained?	shouldn't I have been retaining? shouldn't you have been retaining? shouldn't he have been retaining? shouldn't we have been retaining? shouldn't you have been retaining? shouldn't they have been retaining?