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