I should sniff you should sniff he should sniff we should sniff you should sniff they should sniff
V-ing form
I should be sniffing you should be sniffing he should be sniffing we should be sniffing you should be sniffing they should be sniffing
Perfect
I should have sniffed you should have sniffed he should have sniffed we should have sniffed you should have sniffed they should have sniffed
V-ing perfect
I should have been sniffing you should have been sniffing he should have been sniffing we should have been sniffing you should have been sniffing they should have been sniffing
Negation
Simple form
I should not sniff you should not sniff he should not sniff we should not sniff you should not sniff they should not sniff
V-ing form
I should not be sniffing you should not be sniffing he should not be sniffing we should not be sniffing you should not be sniffing they should not be sniffing
Perfect
I should not have sniffed you should not have sniffed he should not have sniffed we should not have sniffed you should not have sniffed they should not have sniffed
V-ing perfect
I should not have been sniffing you should not have been sniffing he should not have been sniffing we should not have been sniffing you should not have been sniffing they should not have been sniffing
Interrogative form
Simple form
should I sniff? should you sniff? should he sniff? should we sniff? should you sniff? should they sniff?
V-ing form
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
should I have sniffed? should you have sniffed? should he have sniffed? should we have sniffed? should you have sniffed? should they have sniffed?
V-ing perfect
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
should I not sniff? should you not sniff? should he not sniff? should we not sniff? should you not sniff? should they not sniff?
V-ing form
should I not be sniffing? should you not be sniffing? should he not be sniffing? should we not be sniffing? should you not be sniffing? should they not be sniffing?
Perfect
should I not have sniffed? should you not have sniffed? should he not have sniffed? should we not have sniffed? should you not have sniffed? should they not have sniffed?
V-ing perfect
should I not have been sniffing? should you not have been sniffing? should he not have been sniffing? should we not have been sniffing? should you not have been sniffing? should they not have been sniffing?