English verb conjugation
CAN STEM

Regular verb: stem - stemmed - stemmed

Affirmation

Simple form	V-ing form
I can stem you can stem she can stem we can stem you can stem they can stem	I can be stemming you can be stemming she can be stemming we can be stemming you can be stemming they can be stemming
Perfect	V-ing perfect
I can have stemmed you can have stemmed she can have stemmed we can have stemmed you can have stemmed they can have stemmed	I can have been stemming you can have been stemming she can have been stemming we can have been stemming you can have been stemming they can have been stemming

Negation

Simple form	V-ing form
I can't stem you can't stem she can't stem we can't stem you can't stem they can't stem	I can't be stemming you can't be stemming she can't be stemming we can't be stemming you can't be stemming they can't be stemming
Perfect	V-ing perfect
I can't have stemmed you can't have stemmed she can't have stemmed we can't have stemmed you can't have stemmed they can't have stemmed	I can't have been stemming you can't have been stemming she can't have been stemming we can't have been stemming you can't have been stemming they can't have been stemming

Interrogative form

Simple form	V-ing form
can I stem? can you stem? can she stem? can we stem? can you stem? can they stem?	can I be stemming? can you be stemming? can she be stemming? can we be stemming? can you be stemming? can they be stemming?
Perfect	V-ing perfect
can I have stemmed? can you have stemmed? can she have stemmed? can we have stemmed? can you have stemmed? can they have stemmed?	can I have been stemming? can you have been stemming? can she have been stemming? can we have been stemming? can you have been stemming? can they have been stemming?

Interro-negative form

Simple form	V-ing form
can't I stem? can't you stem? can't she stem? can't we stem? can't you stem? can't they stem?	can't I be stemming? can't you be stemming? can't she be stemming? can't we be stemming? can't you be stemming? can't they be stemming?
Perfect	V-ing perfect
can't I have stemmed? can't you have stemmed? can't she have stemmed? can't we have stemmed? can't you have stemmed? can't they have stemmed?	can't I have been stemming? can't you have been stemming? can't she have been stemming? can't we have been stemming? can't you have been stemming? can't they have been stemming?