Conjugación del verbo inglés
COULD STEM

Verbo regular: stem - stemmed - stemmed

Afirmación

Forma simple	Forma con V-ing
I could stem you could stem he could stem we could stem you could stem they could stem	I could be stemming you could be stemming he could be stemming we could be stemming you could be stemming they could be stemming
Perfecto	Perfecto con V-ing
I could have stemmed you could have stemmed he could have stemmed we could have stemmed you could have stemmed they could have stemmed	I could have been stemming you could have been stemming he could have been stemming we could have been stemming you could have been stemming they could have been stemming

Negación

Forma simple	Forma con V-ing
I could not stem you could not stem he could not stem we could not stem you could not stem they could not stem	I could not be stemming you could not be stemming he could not be stemming we could not be stemming you could not be stemming they could not be stemming
Perfecto	Perfecto con V-ing
I could not have stemmed you could not have stemmed he could not have stemmed we could not have stemmed you could not have stemmed they could not have stemmed	I could not have been stemming you could not have been stemming he could not have been stemming we could not have been stemming you could not have been stemming they could not have been stemming

Forma interrogativa

Forma simple	Forma con V-ing
could I stem? could you stem? could he stem? could we stem? could you stem? could they stem?	could I be stemming? could you be stemming? could he be stemming? could we be stemming? could you be stemming? could they be stemming?
Perfecto	Perfecto con V-ing
could I have stemmed? could you have stemmed? could he have stemmed? could we have stemmed? could you have stemmed? could they have stemmed?	could I have been stemming? could you have been stemming? could he have been stemming? could we have been stemming? could you have been stemming? could they have been stemming?

Forma interro-negativa

Forma simple	Forma con V-ing
could I not stem? could you not stem? could he not stem? could we not stem? could you not stem? could they not stem?	could I not be stemming? could you not be stemming? could he not be stemming? could we not be stemming? could you not be stemming? could they not be stemming?
Perfecto	Perfecto con V-ing
could I not have stemmed? could you not have stemmed? could he not have stemmed? could we not have stemmed? could you not have stemmed? could they not have stemmed?	could I not have been stemming? could you not have been stemming? could he not have been stemming? could we not have been stemming? could you not have been stemming? could they not have been stemming?