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