I can bitter you can bitter he can bitter we can bitter you can bitter they can bitter
V-ing form
I can be bittering you can be bittering he can be bittering we can be bittering you can be bittering they can be bittering
Perfect
I can have bittered you can have bittered he can have bittered we can have bittered you can have bittered they can have bittered
V-ing perfect
I can have been bittering you can have been bittering he can have been bittering we can have been bittering you can have been bittering they can have been bittering
Negation
Simple form
I can't bitter you can't bitter he can't bitter we can't bitter you can't bitter they can't bitter
V-ing form
I can't be bittering you can't be bittering he can't be bittering we can't be bittering you can't be bittering they can't be bittering
Perfect
I can't have bittered you can't have bittered he can't have bittered we can't have bittered you can't have bittered they can't have bittered
V-ing perfect
I can't have been bittering you can't have been bittering he can't have been bittering we can't have been bittering you can't have been bittering they can't have been bittering
Interrogative form
Simple form
can I bitter? can you bitter? can he bitter? can we bitter? can you bitter? can they bitter?
V-ing form
can I be bittering? can you be bittering? can he be bittering? can we be bittering? can you be bittering? can they be bittering?
Perfect
can I have bittered? can you have bittered? can he have bittered? can we have bittered? can you have bittered? can they have bittered?
V-ing perfect
can I have been bittering? can you have been bittering? can he have been bittering? can we have been bittering? can you have been bittering? can they have been bittering?
Interro-negative form
Simple form
can't I bitter? can't you bitter? can't he bitter? can't we bitter? can't you bitter? can't they bitter?
V-ing form
can't I be bittering? can't you be bittering? can't he be bittering? can't we be bittering? can't you be bittering? can't they be bittering?
Perfect
can't I have bittered? can't you have bittered? can't he have bittered? can't we have bittered? can't you have bittered? can't they have bittered?
V-ing perfect
can't I have been bittering? can't you have been bittering? can't he have been bittering? can't we have been bittering? can't you have been bittering? can't they have been bittering?