English verb conjugation
CAN FESTER

Regular verb: fester - festered - festered

Affirmation

Simple form	V-ing form
I can fester you can fester he can fester we can fester you can fester they can fester	I can be festering you can be festering he can be festering we can be festering you can be festering they can be festering
Perfect	V-ing perfect
I can have festered you can have festered he can have festered we can have festered you can have festered they can have festered	I can have been festering you can have been festering he can have been festering we can have been festering you can have been festering they can have been festering

Negation

Simple form	V-ing form
I can't fester you can't fester he can't fester we can't fester you can't fester they can't fester	I can't be festering you can't be festering he can't be festering we can't be festering you can't be festering they can't be festering
Perfect	V-ing perfect
I can't have festered you can't have festered he can't have festered we can't have festered you can't have festered they can't have festered	I can't have been festering you can't have been festering he can't have been festering we can't have been festering you can't have been festering they can't have been festering

Interrogative form

Simple form	V-ing form
can I fester? can you fester? can he fester? can we fester? can you fester? can they fester?	can I be festering? can you be festering? can he be festering? can we be festering? can you be festering? can they be festering?
Perfect	V-ing perfect
can I have festered? can you have festered? can he have festered? can we have festered? can you have festered? can they have festered?	can I have been festering? can you have been festering? can he have been festering? can we have been festering? can you have been festering? can they have been festering?

Interro-negative form

Simple form	V-ing form
can't I fester? can't you fester? can't he fester? can't we fester? can't you fester? can't they fester?	can't I be festering? can't you be festering? can't he be festering? can't we be festering? can't you be festering? can't they be festering?
Perfect	V-ing perfect
can't I have festered? can't you have festered? can't he have festered? can't we have festered? can't you have festered? can't they have festered?	can't I have been festering? can't you have been festering? can't he have been festering? can't we have been festering? can't you have been festering? can't they have been festering?