English verb conjugation
CAN BILL

Regular verb: bill - billed - billed

Affirmation

Simple form	V-ing form
I can bill you can bill she can bill we can bill you can bill they can bill	I can be billing you can be billing she can be billing we can be billing you can be billing they can be billing
Perfect	V-ing perfect
I can have billed you can have billed she can have billed we can have billed you can have billed they can have billed	I can have been billing you can have been billing she can have been billing we can have been billing you can have been billing they can have been billing

Negation

Simple form	V-ing form
I cannot bill you cannot bill she cannot bill we cannot bill you cannot bill they cannot bill	I cannot be billing you cannot be billing she cannot be billing we cannot be billing you cannot be billing they cannot be billing
Perfect	V-ing perfect
I cannot have billed you cannot have billed she cannot have billed we cannot have billed you cannot have billed they cannot have billed	I cannot have been billing you cannot have been billing she cannot have been billing we cannot have been billing you cannot have been billing they cannot have been billing

Interrogative form

Simple form	V-ing form
can I bill? can you bill? can she bill? can we bill? can you bill? can they bill?	can I be billing? can you be billing? can she be billing? can we be billing? can you be billing? can they be billing?
Perfect	V-ing perfect
can I have billed? can you have billed? can she have billed? can we have billed? can you have billed? can they have billed?	can I have been billing? can you have been billing? can she have been billing? can we have been billing? can you have been billing? can they have been billing?

Interro-negative form

Simple form	V-ing form
can I not bill? can you not bill? can she not bill? can we not bill? can you not bill? can they not bill?	can I not be billing? can you not be billing? can she not be billing? can we not be billing? can you not be billing? can they not be billing?
Perfect	V-ing perfect
can I not have billed? can you not have billed? can she not have billed? can we not have billed? can you not have billed? can they not have billed?	can I not have been billing? can you not have been billing? can she not have been billing? can we not have been billing? can you not have been billing? can they not have been billing?