English verb conjugation
SHOULD REFER

Regular verb: refer - referred - referred

Affirmation

Simple form	V-ing form
I'd refer you'd refer he'd refer we'd refer you'd refer they'd refer	I'd be referring you'd be referring he'd be referring we'd be referring you'd be referring they'd be referring
Perfect	V-ing perfect
I should've referred you should've referred he should've referred we should've referred you should've referred they should've referred	I should've been referring you should've been referring he should've been referring we should've been referring you should've been referring they should've been referring

Negation

Simple form	V-ing form
I shouldn't refer you shouldn't refer he shouldn't refer we shouldn't refer you shouldn't refer they shouldn't refer	I shouldn't be referring you shouldn't be referring he shouldn't be referring we shouldn't be referring you shouldn't be referring they shouldn't be referring
Perfect	V-ing perfect
I shouldn't have referred you shouldn't have referred he shouldn't have referred we shouldn't have referred you shouldn't have referred they shouldn't have referred	I shouldn't have been referring you shouldn't have been referring he shouldn't have been referring we shouldn't have been referring you shouldn't have been referring they shouldn't have been referring

Interrogative form

Simple form	V-ing form
should I refer? should you refer? should he refer? should we refer? should you refer? should they refer?	should I be referring? should you be referring? should he be referring? should we be referring? should you be referring? should they be referring?
Perfect	V-ing perfect
should I have referred? should you have referred? should he have referred? should we have referred? should you have referred? should they have referred?	should I have been referring? should you have been referring? should he have been referring? should we have been referring? should you have been referring? should they have been referring?

Interro-negative form

Simple form	V-ing form
shouldn't I refer? shouldn't you refer? shouldn't he refer? shouldn't we refer? shouldn't you refer? shouldn't they refer?	shouldn't I be referring? shouldn't you be referring? shouldn't he be referring? shouldn't we be referring? shouldn't you be referring? shouldn't they be referring?
Perfect	V-ing perfect
shouldn't I have referred? shouldn't you have referred? shouldn't he have referred? shouldn't we have referred? shouldn't you have referred? shouldn't they have referred?	shouldn't I have been referring? shouldn't you have been referring? shouldn't he have been referring? shouldn't we have been referring? shouldn't you have been referring? shouldn't they have been referring?