English verb conjugation
CAN SHARPEN

Regular verb: sharpen - sharpened - sharpened

Affirmation

Simple form	V-ing form
I can sharpen you can sharpen she can sharpen we can sharpen you can sharpen they can sharpen	I can be sharpening you can be sharpening she can be sharpening we can be sharpening you can be sharpening they can be sharpening
Perfect	V-ing perfect
I can have sharpened you can have sharpened she can have sharpened we can have sharpened you can have sharpened they can have sharpened	I can have been sharpening you can have been sharpening she can have been sharpening we can have been sharpening you can have been sharpening they can have been sharpening

Negation

Simple form	V-ing form
I can't sharpen you can't sharpen she can't sharpen we can't sharpen you can't sharpen they can't sharpen	I can't be sharpening you can't be sharpening she can't be sharpening we can't be sharpening you can't be sharpening they can't be sharpening
Perfect	V-ing perfect
I can't have sharpened you can't have sharpened she can't have sharpened we can't have sharpened you can't have sharpened they can't have sharpened	I can't have been sharpening you can't have been sharpening she can't have been sharpening we can't have been sharpening you can't have been sharpening they can't have been sharpening

Interrogative form

Simple form	V-ing form
can I sharpen? can you sharpen? can she sharpen? can we sharpen? can you sharpen? can they sharpen?	can I be sharpening? can you be sharpening? can she be sharpening? can we be sharpening? can you be sharpening? can they be sharpening?
Perfect	V-ing perfect
can I have sharpened? can you have sharpened? can she have sharpened? can we have sharpened? can you have sharpened? can they have sharpened?	can I have been sharpening? can you have been sharpening? can she have been sharpening? can we have been sharpening? can you have been sharpening? can they have been sharpening?

Interro-negative form

Simple form	V-ing form
can't I sharpen? can't you sharpen? can't she sharpen? can't we sharpen? can't you sharpen? can't they sharpen?	can't I be sharpening? can't you be sharpening? can't she be sharpening? can't we be sharpening? can't you be sharpening? can't they be sharpening?
Perfect	V-ing perfect
can't I have sharpened? can't you have sharpened? can't she have sharpened? can't we have sharpened? can't you have sharpened? can't they have sharpened?	can't I have been sharpening? can't you have been sharpening? can't she have been sharpening? can't we have been sharpening? can't you have been sharpening? can't they have been sharpening?