English verb conjugation
CAN GAIN

Regular verb: gain - gained - gained

Affirmation

Simple form	V-ing form
I can gain you can gain he can gain we can gain you can gain they can gain	I can be gaining you can be gaining he can be gaining we can be gaining you can be gaining they can be gaining
Perfect	V-ing perfect
I can have gained you can have gained he can have gained we can have gained you can have gained they can have gained	I can have been gaining you can have been gaining he can have been gaining we can have been gaining you can have been gaining they can have been gaining

Negation

Simple form	V-ing form
I can't gain you can't gain he can't gain we can't gain you can't gain they can't gain	I can't be gaining you can't be gaining he can't be gaining we can't be gaining you can't be gaining they can't be gaining
Perfect	V-ing perfect
I can't have gained you can't have gained he can't have gained we can't have gained you can't have gained they can't have gained	I can't have been gaining you can't have been gaining he can't have been gaining we can't have been gaining you can't have been gaining they can't have been gaining

Interrogative form

Simple form	V-ing form
can I gain? can you gain? can he gain? can we gain? can you gain? can they gain?	can I be gaining? can you be gaining? can he be gaining? can we be gaining? can you be gaining? can they be gaining?
Perfect	V-ing perfect
can I have gained? can you have gained? can he have gained? can we have gained? can you have gained? can they have gained?	can I have been gaining? can you have been gaining? can he have been gaining? can we have been gaining? can you have been gaining? can they have been gaining?

Interro-negative form

Simple form	V-ing form
can't I gain? can't you gain? can't he gain? can't we gain? can't you gain? can't they gain?	can't I be gaining? can't you be gaining? can't he be gaining? can't we be gaining? can't you be gaining? can't they be gaining?
Perfect	V-ing perfect
can't I have gained? can't you have gained? can't he have gained? can't we have gained? can't you have gained? can't they have gained?	can't I have been gaining? can't you have been gaining? can't he have been gaining? can't we have been gaining? can't you have been gaining? can't they have been gaining?