English verb conjugation
COULD BIRCH

Regular verb: birch - birched - birched

Affirmation

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

Negation

Simple form	V-ing form
I could not birch you could not birch he could not birch we could not birch you could not birch they could not birch	I could not be birching you could not be birching he could not be birching we could not be birching you could not be birching they could not be birching
Perfect	V-ing perfect
I could not have birched you could not have birched he could not have birched we could not have birched you could not have birched they could not have birched	I could not have been birching you could not have been birching he could not have been birching we could not have been birching you could not have been birching they could not have been birching

Interrogative form

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

Interro-negative form

Simple form	V-ing form
could I not birch? could you not birch? could he not birch? could we not birch? could you not birch? could they not birch?	could I not be birching? could you not be birching? could he not be birching? could we not be birching? could you not be birching? could they not be birching?
Perfect	V-ing perfect
could I not have birched? could you not have birched? could he not have birched? could we not have birched? could you not have birched? could they not have birched?	could I not have been birching? could you not have been birching? could he not have been birching? could we not have been birching? could you not have been birching? could they not have been birching?