English verb conjugation
CAN SPIFF

Regular verb: spiff - spiffed - spiffed

Affirmation

Simple form	V-ing form
I can spiff you can spiff he can spiff we can spiff you can spiff they can spiff	I can be spiffing you can be spiffing he can be spiffing we can be spiffing you can be spiffing they can be spiffing
Perfect	V-ing perfect
I can have spiffed you can have spiffed he can have spiffed we can have spiffed you can have spiffed they can have spiffed	I can have been spiffing you can have been spiffing he can have been spiffing we can have been spiffing you can have been spiffing they can have been spiffing

Negation

Simple form	V-ing form
I cannot spiff you cannot spiff he cannot spiff we cannot spiff you cannot spiff they cannot spiff	I cannot be spiffing you cannot be spiffing he cannot be spiffing we cannot be spiffing you cannot be spiffing they cannot be spiffing
Perfect	V-ing perfect
I cannot have spiffed you cannot have spiffed he cannot have spiffed we cannot have spiffed you cannot have spiffed they cannot have spiffed	I cannot have been spiffing you cannot have been spiffing he cannot have been spiffing we cannot have been spiffing you cannot have been spiffing they cannot have been spiffing

Interrogative form

Simple form	V-ing form
can I spiff? can you spiff? can he spiff? can we spiff? can you spiff? can they spiff?	can I be spiffing? can you be spiffing? can he be spiffing? can we be spiffing? can you be spiffing? can they be spiffing?
Perfect	V-ing perfect
can I have spiffed? can you have spiffed? can he have spiffed? can we have spiffed? can you have spiffed? can they have spiffed?	can I have been spiffing? can you have been spiffing? can he have been spiffing? can we have been spiffing? can you have been spiffing? can they have been spiffing?

Interro-negative form

Simple form	V-ing form
can I not spiff? can you not spiff? can he not spiff? can we not spiff? can you not spiff? can they not spiff?	can I not be spiffing? can you not be spiffing? can he not be spiffing? can we not be spiffing? can you not be spiffing? can they not be spiffing?
Perfect	V-ing perfect
can I not have spiffed? can you not have spiffed? can he not have spiffed? can we not have spiffed? can you not have spiffed? can they not have spiffed?	can I not have been spiffing? can you not have been spiffing? can he not have been spiffing? can we not have been spiffing? can you not have been spiffing? can they not have been spiffing?