I could economize you could economize she could economize we could economize you could economize they could economize
V-ing form
I could be economizing you could be economizing she could be economizing we could be economizing you could be economizing they could be economizing
Perfect
I could have economized you could have economized she could have economized we could have economized you could have economized they could have economized
V-ing perfect
I could have been economizing you could have been economizing she could have been economizing we could have been economizing you could have been economizing they could have been economizing
Negation
Simple form
I couldn't economize you couldn't economize she couldn't economize we couldn't economize you couldn't economize they couldn't economize
V-ing form
I couldn't be economizing you couldn't be economizing she couldn't be economizing we couldn't be economizing you couldn't be economizing they couldn't be economizing
Perfect
I couldn't have economized you couldn't have economized she couldn't have economized we couldn't have economized you couldn't have economized they couldn't have economized
V-ing perfect
I couldn't have been economizing you couldn't have been economizing she couldn't have been economizing we couldn't have been economizing you couldn't have been economizing they couldn't have been economizing
Interrogative form
Simple form
could I economize? could you economize? could she economize? could we economize? could you economize? could they economize?
V-ing form
could I be economizing? could you be economizing? could she be economizing? could we be economizing? could you be economizing? could they be economizing?
Perfect
could I have economized? could you have economized? could she have economized? could we have economized? could you have economized? could they have economized?
V-ing perfect
could I have been economizing? could you have been economizing? could she have been economizing? could we have been economizing? could you have been economizing? could they have been economizing?
Interro-negative form
Simple form
couldn't I economize? couldn't you economize? couldn't she economize? couldn't we economize? couldn't you economize? couldn't they economize?
V-ing form
couldn't I be economizing? couldn't you be economizing? couldn't she be economizing? couldn't we be economizing? couldn't you be economizing? couldn't they be economizing?
Perfect
couldn't I have economized? couldn't you have economized? couldn't she have economized? couldn't we have economized? couldn't you have economized? couldn't they have economized?
V-ing perfect
couldn't I have been economizing? couldn't you have been economizing? couldn't she have been economizing? couldn't we have been economizing? couldn't you have been economizing? couldn't they have been economizing?