English verb conjugation
SHOULD SNIFF

Regular verb: sniff - sniffed - sniffed

Affirmation

Simple form	V-ing form
I'd sniff you'd sniff he'd sniff we'd sniff you'd sniff they'd sniff	I'd be sniffing you'd be sniffing he'd be sniffing we'd be sniffing you'd be sniffing they'd be sniffing
Perfect	V-ing perfect
I should've sniffed you should've sniffed he should've sniffed we should've sniffed you should've sniffed they should've sniffed	I should've been sniffing you should've been sniffing he should've been sniffing we should've been sniffing you should've been sniffing they should've been sniffing

Negation

Simple form	V-ing form
I shouldn't sniff you shouldn't sniff he shouldn't sniff we shouldn't sniff you shouldn't sniff they shouldn't sniff	I shouldn't be sniffing you shouldn't be sniffing he shouldn't be sniffing we shouldn't be sniffing you shouldn't be sniffing they shouldn't be sniffing
Perfect	V-ing perfect
I shouldn't have sniffed you shouldn't have sniffed he shouldn't have sniffed we shouldn't have sniffed you shouldn't have sniffed they shouldn't have sniffed	I shouldn't have been sniffing you shouldn't have been sniffing he shouldn't have been sniffing we shouldn't have been sniffing you shouldn't have been sniffing they shouldn't have been sniffing

Interrogative form

Simple form	V-ing form
should I sniff? should you sniff? should he sniff? should we sniff? should you sniff? should they sniff?	should I be sniffing? should you be sniffing? should he be sniffing? should we be sniffing? should you be sniffing? should they be sniffing?
Perfect	V-ing perfect
should I have sniffed? should you have sniffed? should he have sniffed? should we have sniffed? should you have sniffed? should they have sniffed?	should I have been sniffing? should you have been sniffing? should he have been sniffing? should we have been sniffing? should you have been sniffing? should they have been sniffing?

Interro-negative form

Simple form	V-ing form
shouldn't I sniff? shouldn't you sniff? shouldn't he sniff? shouldn't we sniff? shouldn't you sniff? shouldn't they sniff?	shouldn't I be sniffing? shouldn't you be sniffing? shouldn't he be sniffing? shouldn't we be sniffing? shouldn't you be sniffing? shouldn't they be sniffing?
Perfect	V-ing perfect
shouldn't I have sniffed? shouldn't you have sniffed? shouldn't he have sniffed? shouldn't we have sniffed? shouldn't you have sniffed? shouldn't they have sniffed?	shouldn't I have been sniffing? shouldn't you have been sniffing? shouldn't he have been sniffing? shouldn't we have been sniffing? shouldn't you have been sniffing? shouldn't they have been sniffing?