can bitter
Regular verb: bitter - bittered- bittered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can bitter
you can bitter
he can bitter
we can bitter
you can bitter
they can bitter 	I can be bittering
you can be bittering
he can be bittering
we can be bittering
you can be bittering
they can be bittering	I can have bittered
you can have bittered
he can have bittered
we can have bittered
you can have bittered
they can have bittered	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 	V-ing form 	Perfect 	V-ing perfect 	
I can't bitter
you can't bitter
he can't bitter
we can't bitter
you can't bitter
they can't bitter 	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	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	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 	V-ing form 	Perfect 	V-ing perfect 	
can I bitter?
can you bitter?
can he bitter?
can we bitter?
can you bitter?
can they bitter? 	can I be bittering?
can you be bittering?
can he be bittering?
can we be bittering?
can you be bittering?
can they be bittering? 	can I have bittered?
can you have bittered?
can he have bittered?
can we have bittered?
can you have bittered?
can they have bittered? 	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 	V-ing form 	Perfect 	V-ing perfect 	
can't I bitter?
can't you bitter?
can't he bitter?
can't we bitter?
can't you bitter?
can't they bitter? 	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? 	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? 	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?