English verb conjugation
CAN BIRCH

Regular verb: birch - birched - birched

Affirmation

Simple form	V-ing form
I can birch you can birch he can birch we can birch you can birch they can birch	I can be birching you can be birching he can be birching we can be birching you can be birching they can be birching
Perfect	V-ing perfect
I can have birched you can have birched he can have birched we can have birched you can have birched they can have birched	I can have been birching you can have been birching he can have been birching we can have been birching you can have been birching they can have been birching

Negation

Simple form	V-ing form
I can't birch you can't birch he can't birch we can't birch you can't birch they can't birch	I can't be birching you can't be birching he can't be birching we can't be birching you can't be birching they can't be birching
Perfect	V-ing perfect
I can't have birched you can't have birched he can't have birched we can't have birched you can't have birched they can't have birched	I can't have been birching you can't have been birching he can't have been birching we can't have been birching you can't have been birching they can't have been birching

Interrogative form

Simple form	V-ing form
can I birch? can you birch? can he birch? can we birch? can you birch? can they birch?	can I be birching? can you be birching? can he be birching? can we be birching? can you be birching? can they be birching?
Perfect	V-ing perfect
can I have birched? can you have birched? can he have birched? can we have birched? can you have birched? can they have birched?	can I have been birching? can you have been birching? can he have been birching? can we have been birching? can you have been birching? can they have been birching?

Interro-negative form

Simple form	V-ing form
can't I birch? can't you birch? can't he birch? can't we birch? can't you birch? can't they birch?	can't I be birching? can't you be birching? can't he be birching? can't we be birching? can't you be birching? can't they be birching?
Perfect	V-ing perfect
can't I have birched? can't you have birched? can't he have birched? can't we have birched? can't you have birched? can't they have birched?	can't I have been birching? can't you have been birching? can't he have been birching? can't we have been birching? can't you have been birching? can't they have been birching?