English verb conjugation
CAN MASTER

Regular verb: master - mastered - mastered

Affirmation

Simple form	V-ing form
I can master you can master he can master we can master you can master they can master	I can be mastering you can be mastering he can be mastering we can be mastering you can be mastering they can be mastering
Perfect	V-ing perfect
I can have mastered you can have mastered he can have mastered we can have mastered you can have mastered they can have mastered	I can have been mastering you can have been mastering he can have been mastering we can have been mastering you can have been mastering they can have been mastering

Negation

Simple form	V-ing form
I can't master you can't master he can't master we can't master you can't master they can't master	I can't be mastering you can't be mastering he can't be mastering we can't be mastering you can't be mastering they can't be mastering
Perfect	V-ing perfect
I can't have mastered you can't have mastered he can't have mastered we can't have mastered you can't have mastered they can't have mastered	I can't have been mastering you can't have been mastering he can't have been mastering we can't have been mastering you can't have been mastering they can't have been mastering

Interrogative form

Simple form	V-ing form
can I master? can you master? can he master? can we master? can you master? can they master?	can I be mastering? can you be mastering? can he be mastering? can we be mastering? can you be mastering? can they be mastering?
Perfect	V-ing perfect
can I have mastered? can you have mastered? can he have mastered? can we have mastered? can you have mastered? can they have mastered?	can I have been mastering? can you have been mastering? can he have been mastering? can we have been mastering? can you have been mastering? can they have been mastering?

Interro-negative form

Simple form	V-ing form
can't I master? can't you master? can't he master? can't we master? can't you master? can't they master?	can't I be mastering? can't you be mastering? can't he be mastering? can't we be mastering? can't you be mastering? can't they be mastering?
Perfect	V-ing perfect
can't I have mastered? can't you have mastered? can't he have mastered? can't we have mastered? can't you have mastered? can't they have mastered?	can't I have been mastering? can't you have been mastering? can't he have been mastering? can't we have been mastering? can't you have been mastering? can't they have been mastering?