English verb conjugation
CAN FESTER

Regular verb: fester - festered - festered

Affirmation

Simple form	V-ing form
I can fester you can fester she can fester we can fester you can fester they can fester	I can be festering you can be festering she 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 she 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 she 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 cannot fester you cannot fester she cannot fester we cannot fester you cannot fester they cannot fester	I cannot be festering you cannot be festering she cannot be festering we cannot be festering you cannot be festering they cannot be festering
Perfect	V-ing perfect
I cannot have festered you cannot have festered she cannot have festered we cannot have festered you cannot have festered they cannot have festered	I cannot have been festering you cannot have been festering she cannot have been festering we cannot have been festering you cannot have been festering they cannot have been festering

Interrogative form

Simple form	V-ing form
can I fester? can you fester? can she fester? can we fester? can you fester? can they fester?	can I be festering? can you be festering? can she 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 she 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 she 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 I not fester? can you not fester? can she not fester? can we not fester? can you not fester? can they not fester?	can I not be festering? can you not be festering? can she not be festering? can we not be festering? can you not be festering? can they not be festering?
Perfect	V-ing perfect
can I not have festered? can you not have festered? can she not have festered? can we not have festered? can you not have festered? can they not have festered?	can I not have been festering? can you not have been festering? can she not have been festering? can we not have been festering? can you not have been festering? can they not have been festering?