English verb conjugation
COULD EXCHANGE

Regular verb: exchange - exchanged - exchanged

Affirmation

Simple form	V-ing form
I could exchange you could exchange he could exchange we could exchange you could exchange they could exchange	I could be exchanging you could be exchanging he could be exchanging we could be exchanging you could be exchanging they could be exchanging
Perfect	V-ing perfect
I could have exchanged you could have exchanged he could have exchanged we could have exchanged you could have exchanged they could have exchanged	I could have been exchanging you could have been exchanging he could have been exchanging we could have been exchanging you could have been exchanging they could have been exchanging

Negation

Simple form	V-ing form
I couldn't exchange you couldn't exchange he couldn't exchange we couldn't exchange you couldn't exchange they couldn't exchange	I couldn't be exchanging you couldn't be exchanging he couldn't be exchanging we couldn't be exchanging you couldn't be exchanging they couldn't be exchanging
Perfect	V-ing perfect
I couldn't have exchanged you couldn't have exchanged he couldn't have exchanged we couldn't have exchanged you couldn't have exchanged they couldn't have exchanged	I couldn't have been exchanging you couldn't have been exchanging he couldn't have been exchanging we couldn't have been exchanging you couldn't have been exchanging they couldn't have been exchanging

Interrogative form

Simple form	V-ing form
could I exchange? could you exchange? could he exchange? could we exchange? could you exchange? could they exchange?	could I be exchanging? could you be exchanging? could he be exchanging? could we be exchanging? could you be exchanging? could they be exchanging?
Perfect	V-ing perfect
could I have exchanged? could you have exchanged? could he have exchanged? could we have exchanged? could you have exchanged? could they have exchanged?	could I have been exchanging? could you have been exchanging? could he have been exchanging? could we have been exchanging? could you have been exchanging? could they have been exchanging?

Interro-negative form

Simple form	V-ing form
couldn't I exchange? couldn't you exchange? couldn't he exchange? couldn't we exchange? couldn't you exchange? couldn't they exchange?	couldn't I be exchanging? couldn't you be exchanging? couldn't he be exchanging? couldn't we be exchanging? couldn't you be exchanging? couldn't they be exchanging?
Perfect	V-ing perfect
couldn't I have exchanged? couldn't you have exchanged? couldn't he have exchanged? couldn't we have exchanged? couldn't you have exchanged? couldn't they have exchanged?	couldn't I have been exchanging? couldn't you have been exchanging? couldn't he have been exchanging? couldn't we have been exchanging? couldn't you have been exchanging? couldn't they have been exchanging?