English verb conjugation
CAN RETAIN

Regular verb: retain - retained - retained

Affirmation

Simple form	V-ing form
I can retain you can retain she can retain we can retain you can retain they can retain	I can be retaining you can be retaining she can be retaining we can be retaining you can be retaining they can be retaining
Perfect	V-ing perfect
I can have retained you can have retained she can have retained we can have retained you can have retained they can have retained	I can have been retaining you can have been retaining she can have been retaining we can have been retaining you can have been retaining they can have been retaining

Negation

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

Interrogative form

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

Interro-negative form

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