Conjugação do verbo inglês
COULD STEM

Verbo regular: stem - stemmed - stemmed

Afirmação

Forma simple	Forma com 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
Perfeito	Perfeito com 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

Negação

Forma simple	Forma com V-ing
I couldn't stem you couldn't stem he couldn't stem we couldn't stem you couldn't stem they couldn't stem	I couldn't be stemming you couldn't be stemming he couldn't be stemming we couldn't be stemming you couldn't be stemming they couldn't be stemming
Perfeito	Perfeito com V-ing
I couldn't have stemmed you couldn't have stemmed he couldn't have stemmed we couldn't have stemmed you couldn't have stemmed they couldn't have stemmed	I couldn't have been stemming you couldn't have been stemming he couldn't have been stemming we couldn't have been stemming you couldn't have been stemming they couldn't have been stemming

Forma interrogativa

Forma simple	Forma com 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?
Perfeito	Perfeito com 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-Negação

Forma simple	Forma com V-ing
couldn't I stem? couldn't you stem? couldn't he stem? couldn't we stem? couldn't you stem? couldn't they stem?	couldn't I be stemming? couldn't you be stemming? couldn't he be stemming? couldn't we be stemming? couldn't you be stemming? couldn't they be stemming?
Perfeito	Perfeito com V-ing
couldn't I have stemmed? couldn't you have stemmed? couldn't he have stemmed? couldn't we have stemmed? couldn't you have stemmed? couldn't they have stemmed?	couldn't I have been stemming? couldn't you have been stemming? couldn't he have been stemming? couldn't we have been stemming? couldn't you have been stemming? couldn't they have been stemming?