English verb conjugation
COULD EARN

Regular verb: earn - earned - earned

Affirmation

Simple form	V-ing form
I could earn you could earn he could earn we could earn you could earn they could earn	I could be earning you could be earning he 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 he 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 he 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 couldn't earn you couldn't earn he couldn't earn we couldn't earn you couldn't earn they couldn't earn	I couldn't be earning you couldn't be earning he couldn't be earning we couldn't be earning you couldn't be earning they couldn't be earning
Perfect	V-ing perfect
I couldn't have earned you couldn't have earned he couldn't have earned we couldn't have earned you couldn't have earned they couldn't have earned	I couldn't have been earning you couldn't have been earning he couldn't have been earning we couldn't have been earning you couldn't have been earning they couldn't have been earning

Interrogative form

Simple form	V-ing form
could I earn? could you earn? could he earn? could we earn? could you earn? could they earn?	could I be earning? could you be earning? could he 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 he 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 he 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
couldn't I earn? couldn't you earn? couldn't he earn? couldn't we earn? couldn't you earn? couldn't they earn?	couldn't I be earning? couldn't you be earning? couldn't he be earning? couldn't we be earning? couldn't you be earning? couldn't they be earning?
Perfect	V-ing perfect
couldn't I have earned? couldn't you have earned? couldn't he have earned? couldn't we have earned? couldn't you have earned? couldn't they have earned?	couldn't I have been earning? couldn't you have been earning? couldn't he have been earning? couldn't we have been earning? couldn't you have been earning? couldn't they have been earning?