English verb conjugation
CAN SNIFF

Regular verb: sniff - sniffed - sniffed

Affirmation

Simple form	V-ing form
I can sniff you can sniff she can sniff we can sniff you can sniff they can sniff	I can be sniffing you can be sniffing she can be sniffing we can be sniffing you can be sniffing they can be sniffing
Perfect	V-ing perfect
I can have sniffed you can have sniffed she can have sniffed we can have sniffed you can have sniffed they can have sniffed	I can have been sniffing you can have been sniffing she can have been sniffing we can have been sniffing you can have been sniffing they can have been sniffing

Negation

Simple form	V-ing form
I cannot sniff you cannot sniff she cannot sniff we cannot sniff you cannot sniff they cannot sniff	I cannot be sniffing you cannot be sniffing she cannot be sniffing we cannot be sniffing you cannot be sniffing they cannot be sniffing
Perfect	V-ing perfect
I cannot have sniffed you cannot have sniffed she cannot have sniffed we cannot have sniffed you cannot have sniffed they cannot have sniffed	I cannot have been sniffing you cannot have been sniffing she cannot have been sniffing we cannot have been sniffing you cannot have been sniffing they cannot have been sniffing

Interrogative form

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

Interro-negative form

Simple form	V-ing form
can I not sniff? can you not sniff? can she not sniff? can we not sniff? can you not sniff? can they not sniff?	can I not be sniffing? can you not be sniffing? can she not be sniffing? can we not be sniffing? can you not be sniffing? can they not be sniffing?
Perfect	V-ing perfect
can I not have sniffed? can you not have sniffed? can she not have sniffed? can we not have sniffed? can you not have sniffed? can they not have sniffed?	can I not have been sniffing? can you not have been sniffing? can she not have been sniffing? can we not have been sniffing? can you not have been sniffing? can they not have been sniffing?