English verb conjugation
CAN LUFF

Regular verb: luff - luffed - luffed

Affirmation

Simple form	V-ing form
I can luff you can luff he can luff we can luff you can luff they can luff	I can be luffing you can be luffing he can be luffing we can be luffing you can be luffing they can be luffing
Perfect	V-ing perfect
I can have luffed you can have luffed he can have luffed we can have luffed you can have luffed they can have luffed	I can have been luffing you can have been luffing he can have been luffing we can have been luffing you can have been luffing they can have been luffing

Negation

Simple form	V-ing form
I can't luff you can't luff he can't luff we can't luff you can't luff they can't luff	I can't be luffing you can't be luffing he can't be luffing we can't be luffing you can't be luffing they can't be luffing
Perfect	V-ing perfect
I can't have luffed you can't have luffed he can't have luffed we can't have luffed you can't have luffed they can't have luffed	I can't have been luffing you can't have been luffing he can't have been luffing we can't have been luffing you can't have been luffing they can't have been luffing

Interrogative form

Simple form	V-ing form
can I luff? can you luff? can he luff? can we luff? can you luff? can they luff?	can I be luffing? can you be luffing? can he be luffing? can we be luffing? can you be luffing? can they be luffing?
Perfect	V-ing perfect
can I have luffed? can you have luffed? can he have luffed? can we have luffed? can you have luffed? can they have luffed?	can I have been luffing? can you have been luffing? can he have been luffing? can we have been luffing? can you have been luffing? can they have been luffing?

Interro-negative form

Simple form	V-ing form
can't I luff? can't you luff? can't he luff? can't we luff? can't you luff? can't they luff?	can't I be luffing? can't you be luffing? can't he be luffing? can't we be luffing? can't you be luffing? can't they be luffing?
Perfect	V-ing perfect
can't I have luffed? can't you have luffed? can't he have luffed? can't we have luffed? can't you have luffed? can't they have luffed?	can't I have been luffing? can't you have been luffing? can't he have been luffing? can't we have been luffing? can't you have been luffing? can't they have been luffing?