English verb conjugation
CAN FASTEN

Regular verb: fasten - fastened - fastened

Affirmation

Simple form	V-ing form
I can fasten you can fasten he can fasten we can fasten you can fasten they can fasten	I can be fastening you can be fastening he can be fastening we can be fastening you can be fastening they can be fastening
Perfect	V-ing perfect
I can have fastened you can have fastened he can have fastened we can have fastened you can have fastened they can have fastened	I can have been fastening you can have been fastening he can have been fastening we can have been fastening you can have been fastening they can have been fastening

Negation

Simple form	V-ing form
I can't fasten you can't fasten he can't fasten we can't fasten you can't fasten they can't fasten	I can't be fastening you can't be fastening he can't be fastening we can't be fastening you can't be fastening they can't be fastening
Perfect	V-ing perfect
I can't have fastened you can't have fastened he can't have fastened we can't have fastened you can't have fastened they can't have fastened	I can't have been fastening you can't have been fastening he can't have been fastening we can't have been fastening you can't have been fastening they can't have been fastening

Interrogative form

Simple form	V-ing form
can I fasten? can you fasten? can he fasten? can we fasten? can you fasten? can they fasten?	can I be fastening? can you be fastening? can he be fastening? can we be fastening? can you be fastening? can they be fastening?
Perfect	V-ing perfect
can I have fastened? can you have fastened? can he have fastened? can we have fastened? can you have fastened? can they have fastened?	can I have been fastening? can you have been fastening? can he have been fastening? can we have been fastening? can you have been fastening? can they have been fastening?

Interro-negative form

Simple form	V-ing form
can't I fasten? can't you fasten? can't he fasten? can't we fasten? can't you fasten? can't they fasten?	can't I be fastening? can't you be fastening? can't he be fastening? can't we be fastening? can't you be fastening? can't they be fastening?
Perfect	V-ing perfect
can't I have fastened? can't you have fastened? can't he have fastened? can't we have fastened? can't you have fastened? can't they have fastened?	can't I have been fastening? can't you have been fastening? can't he have been fastening? can't we have been fastening? can't you have been fastening? can't they have been fastening?