I could abbreviate you could abbreviate he could abbreviate we could abbreviate you could abbreviate they could abbreviate
V-ing form
I could be abbreviating you could be abbreviating he could be abbreviating we could be abbreviating you could be abbreviating they could be abbreviating
Perfect
I could have abbreviated you could have abbreviated he could have abbreviated we could have abbreviated you could have abbreviated they could have abbreviated
V-ing perfect
I could have been abbreviating you could have been abbreviating he could have been abbreviating we could have been abbreviating you could have been abbreviating they could have been abbreviating
Negation
Simple form
I couldn't abbreviate you couldn't abbreviate he couldn't abbreviate we couldn't abbreviate you couldn't abbreviate they couldn't abbreviate
V-ing form
I couldn't be abbreviating you couldn't be abbreviating he couldn't be abbreviating we couldn't be abbreviating you couldn't be abbreviating they couldn't be abbreviating
Perfect
I couldn't have abbreviated you couldn't have abbreviated he couldn't have abbreviated we couldn't have abbreviated you couldn't have abbreviated they couldn't have abbreviated
V-ing perfect
I couldn't have been abbreviating you couldn't have been abbreviating he couldn't have been abbreviating we couldn't have been abbreviating you couldn't have been abbreviating they couldn't have been abbreviating
Interrogative form
Simple form
could I abbreviate? could you abbreviate? could he abbreviate? could we abbreviate? could you abbreviate? could they abbreviate?
V-ing form
could I be abbreviating? could you be abbreviating? could he be abbreviating? could we be abbreviating? could you be abbreviating? could they be abbreviating?
Perfect
could I have abbreviated? could you have abbreviated? could he have abbreviated? could we have abbreviated? could you have abbreviated? could they have abbreviated?
V-ing perfect
could I have been abbreviating? could you have been abbreviating? could he have been abbreviating? could we have been abbreviating? could you have been abbreviating? could they have been abbreviating?
Interro-negative form
Simple form
couldn't I abbreviate? couldn't you abbreviate? couldn't he abbreviate? couldn't we abbreviate? couldn't you abbreviate? couldn't they abbreviate?
V-ing form
couldn't I be abbreviating? couldn't you be abbreviating? couldn't he be abbreviating? couldn't we be abbreviating? couldn't you be abbreviating? couldn't they be abbreviating?
Perfect
couldn't I have abbreviated? couldn't you have abbreviated? couldn't he have abbreviated? couldn't we have abbreviated? couldn't you have abbreviated? couldn't they have abbreviated?
V-ing perfect
couldn't I have been abbreviating? couldn't you have been abbreviating? couldn't he have been abbreviating? couldn't we have been abbreviating? couldn't you have been abbreviating? couldn't they have been abbreviating?