English verb conjugation
CAN SPIFF

Regular verb: spiff - spiffed - spiffed

Affirmation

Simple form	V-ing form
I can spiff you can spiff she can spiff we can spiff you can spiff they can spiff	I can be spiffing you can be spiffing she 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 she 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 she 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 can't spiff you can't spiff she can't spiff we can't spiff you can't spiff they can't spiff	I can't be spiffing you can't be spiffing she can't be spiffing we can't be spiffing you can't be spiffing they can't be spiffing
Perfect	V-ing perfect
I can't have spiffed you can't have spiffed she can't have spiffed we can't have spiffed you can't have spiffed they can't have spiffed	I can't have been spiffing you can't have been spiffing she can't have been spiffing we can't have been spiffing you can't have been spiffing they can't have been spiffing

Interrogative form

Simple form	V-ing form
can I spiff? can you spiff? can she spiff? can we spiff? can you spiff? can they spiff?	can I be spiffing? can you be spiffing? can she 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 she 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 she 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't I spiff? can't you spiff? can't she spiff? can't we spiff? can't you spiff? can't they spiff?	can't I be spiffing? can't you be spiffing? can't she be spiffing? can't we be spiffing? can't you be spiffing? can't they be spiffing?
Perfect	V-ing perfect
can't I have spiffed? can't you have spiffed? can't she have spiffed? can't we have spiffed? can't you have spiffed? can't they have spiffed?	can't I have been spiffing? can't you have been spiffing? can't she have been spiffing? can't we have been spiffing? can't you have been spiffing? can't they have been spiffing?