I should bill you should bill he should bill we should bill you should bill they should bill
V-ing form
I should be billing you should be billing he should be billing we should be billing you should be billing they should be billing
Perfect
I should have billed you should have billed he should have billed we should have billed you should have billed they should have billed
V-ing perfect
I should have been billing you should have been billing he should have been billing we should have been billing you should have been billing they should have been billing
Negation
Simple form
I should not bill you should not bill he should not bill we should not bill you should not bill they should not bill
V-ing form
I should not be billing you should not be billing he should not be billing we should not be billing you should not be billing they should not be billing
Perfect
I should not have billed you should not have billed he should not have billed we should not have billed you should not have billed they should not have billed
V-ing perfect
I should not have been billing you should not have been billing he should not have been billing we should not have been billing you should not have been billing they should not have been billing
Interrogative form
Simple form
should I bill? should you bill? should he bill? should we bill? should you bill? should they bill?
V-ing form
should I be billing? should you be billing? should he be billing? should we be billing? should you be billing? should they be billing?
Perfect
should I have billed? should you have billed? should he have billed? should we have billed? should you have billed? should they have billed?
V-ing perfect
should I have been billing? should you have been billing? should he have been billing? should we have been billing? should you have been billing? should they have been billing?
Interro-negative form
Simple form
should I not bill? should you not bill? should he not bill? should we not bill? should you not bill? should they not bill?
V-ing form
should I not be billing? should you not be billing? should he not be billing? should we not be billing? should you not be billing? should they not be billing?
Perfect
should I not have billed? should you not have billed? should he not have billed? should we not have billed? should you not have billed? should they not have billed?
V-ing perfect
should I not have been billing? should you not have been billing? should he not have been billing? should we not have been billing? should you not have been billing? should they not have been billing?