English verb conjugation
CAN FIGHT

Irregular verb: fight - fought - fought

Affirmation

Simple form	V-ing form
I can fight you can fight he can fight we can fight you can fight they can fight	I can be fighting you can be fighting he can be fighting we can be fighting you can be fighting they can be fighting
Perfect	V-ing perfect
I can have fought you can have fought he can have fought we can have fought you can have fought they can have fought	I can have been fighting you can have been fighting he can have been fighting we can have been fighting you can have been fighting they can have been fighting

Negation

Simple form	V-ing form
I can't fight you can't fight he can't fight we can't fight you can't fight they can't fight	I can't be fighting you can't be fighting he can't be fighting we can't be fighting you can't be fighting they can't be fighting
Perfect	V-ing perfect
I can't have fought you can't have fought he can't have fought we can't have fought you can't have fought they can't have fought	I can't have been fighting you can't have been fighting he can't have been fighting we can't have been fighting you can't have been fighting they can't have been fighting

Interrogative form

Simple form	V-ing form
can I fight? can you fight? can he fight? can we fight? can you fight? can they fight?	can I be fighting? can you be fighting? can he be fighting? can we be fighting? can you be fighting? can they be fighting?
Perfect	V-ing perfect
can I have fought? can you have fought? can he have fought? can we have fought? can you have fought? can they have fought?	can I have been fighting? can you have been fighting? can he have been fighting? can we have been fighting? can you have been fighting? can they have been fighting?

Interro-negative form

Simple form	V-ing form
can't I fight? can't you fight? can't he fight? can't we fight? can't you fight? can't they fight?	can't I be fighting? can't you be fighting? can't he be fighting? can't we be fighting? can't you be fighting? can't they be fighting?
Perfect	V-ing perfect
can't I have fought? can't you have fought? can't he have fought? can't we have fought? can't you have fought? can't they have fought?	can't I have been fighting? can't you have been fighting? can't he have been fighting? can't we have been fighting? can't you have been fighting? can't they have been fighting?