English verb conjugation
CAN BIFF

Regular verb: biff - biffed - biffed

Affirmation

Simple form	V-ing form
I can biff you can biff he can biff we can biff you can biff they can biff	I can be biffing you can be biffing he can be biffing we can be biffing you can be biffing they can be biffing
Perfect	V-ing perfect
I can have biffed you can have biffed he can have biffed we can have biffed you can have biffed they can have biffed	I can have been biffing you can have been biffing he can have been biffing we can have been biffing you can have been biffing they can have been biffing

Negation

Simple form	V-ing form
I can't biff you can't biff he can't biff we can't biff you can't biff they can't biff	I can't be biffing you can't be biffing he can't be biffing we can't be biffing you can't be biffing they can't be biffing
Perfect	V-ing perfect
I can't have biffed you can't have biffed he can't have biffed we can't have biffed you can't have biffed they can't have biffed	I can't have been biffing you can't have been biffing he can't have been biffing we can't have been biffing you can't have been biffing they can't have been biffing

Interrogative form

Simple form	V-ing form
can I biff? can you biff? can he biff? can we biff? can you biff? can they biff?	can I be biffing? can you be biffing? can he be biffing? can we be biffing? can you be biffing? can they be biffing?
Perfect	V-ing perfect
can I have biffed? can you have biffed? can he have biffed? can we have biffed? can you have biffed? can they have biffed?	can I have been biffing? can you have been biffing? can he have been biffing? can we have been biffing? can you have been biffing? can they have been biffing?

Interro-negative form

Simple form	V-ing form
can't I biff? can't you biff? can't he biff? can't we biff? can't you biff? can't they biff?	can't I be biffing? can't you be biffing? can't he be biffing? can't we be biffing? can't you be biffing? can't they be biffing?
Perfect	V-ing perfect
can't I have biffed? can't you have biffed? can't he have biffed? can't we have biffed? can't you have biffed? can't they have biffed?	can't I have been biffing? can't you have been biffing? can't he have been biffing? can't we have been biffing? can't you have been biffing? can't they have been biffing?