I could bud you could bud she could bud we could bud you could bud they could bud
V-ing form
I could be budding you could be budding she could be budding we could be budding you could be budding they could be budding
Perfect
I could have budded you could have budded she 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 she 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 she 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 she 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 she 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 she 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 she bud? could we bud? could you bud? could they bud?
V-ing form
could I be budding? could you be budding? could she be budding? could we be budding? could you be budding? could they be budding?
Perfect
could I have budded? could you have budded? could she 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 she 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 she 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 she 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 she 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 she have been budding? couldn't we have been budding? couldn't you have been budding? couldn't they have been budding?