English verb conjugation
COULD EARN

Regular verb: earn - earned - earned

Affirmation

Simple form	V-ing form
I could earn you could earn she could earn we could earn you could earn they could earn	I could be earning you could be earning she could be earning we could be earning you could be earning they could be earning
Perfect	V-ing perfect
I could have earned you could have earned she could have earned we could have earned you could have earned they could have earned	I could have been earning you could have been earning she could have been earning we could have been earning you could have been earning they could have been earning

Negation

Simple form	V-ing form
I could not earn you could not earn she could not earn we could not earn you could not earn they could not earn	I could not be earning you could not be earning she could not be earning we could not be earning you could not be earning they could not be earning
Perfect	V-ing perfect
I could not have earned you could not have earned she could not have earned we could not have earned you could not have earned they could not have earned	I could not have been earning you could not have been earning she could not have been earning we could not have been earning you could not have been earning they could not have been earning

Interrogative form

Simple form	V-ing form
could I earn? could you earn? could she earn? could we earn? could you earn? could they earn?	could I be earning? could you be earning? could she be earning? could we be earning? could you be earning? could they be earning?
Perfect	V-ing perfect
could I have earned? could you have earned? could she have earned? could we have earned? could you have earned? could they have earned?	could I have been earning? could you have been earning? could she have been earning? could we have been earning? could you have been earning? could they have been earning?

Interro-negative form

Simple form	V-ing form
could I not earn? could you not earn? could she not earn? could we not earn? could you not earn? could they not earn?	could I not be earning? could you not be earning? could she not be earning? could we not be earning? could you not be earning? could they not be earning?
Perfect	V-ing perfect
could I not have earned? could you not have earned? could she not have earned? could we not have earned? could you not have earned? could they not have earned?	could I not have been earning? could you not have been earning? could she not have been earning? could we not have been earning? could you not have been earning? could they not have been earning?