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