Conjugación del verbo inglés
COULD SUSTAIN

Verbo regular: sustain - sustained - sustained

Afirmación

Forma simple	Forma con V-ing
I could sustain you could sustain he could sustain we could sustain you could sustain they could sustain	I could be sustaining you could be sustaining he could be sustaining we could be sustaining you could be sustaining they could be sustaining
Perfecto	Perfecto con V-ing
I could have sustained you could have sustained he could have sustained we could have sustained you could have sustained they could have sustained	I could have been sustaining you could have been sustaining he could have been sustaining we could have been sustaining you could have been sustaining they could have been sustaining

Negación

Forma simple	Forma con V-ing
I could not sustain you could not sustain he could not sustain we could not sustain you could not sustain they could not sustain	I could not be sustaining you could not be sustaining he could not be sustaining we could not be sustaining you could not be sustaining they could not be sustaining
Perfecto	Perfecto con V-ing
I could not have sustained you could not have sustained he could not have sustained we could not have sustained you could not have sustained they could not have sustained	I could not have been sustaining you could not have been sustaining he could not have been sustaining we could not have been sustaining you could not have been sustaining they could not have been sustaining

Forma interrogativa

Forma simple	Forma con V-ing
could I sustain? could you sustain? could he sustain? could we sustain? could you sustain? could they sustain?	could I be sustaining? could you be sustaining? could he be sustaining? could we be sustaining? could you be sustaining? could they be sustaining?
Perfecto	Perfecto con V-ing
could I have sustained? could you have sustained? could he have sustained? could we have sustained? could you have sustained? could they have sustained?	could I have been sustaining? could you have been sustaining? could he have been sustaining? could we have been sustaining? could you have been sustaining? could they have been sustaining?

Forma interro-negativa

Forma simple	Forma con V-ing
could I not sustain? could you not sustain? could he not sustain? could we not sustain? could you not sustain? could they not sustain?	could I not be sustaining? could you not be sustaining? could he not be sustaining? could we not be sustaining? could you not be sustaining? could they not be sustaining?
Perfecto	Perfecto con V-ing
could I not have sustained? could you not have sustained? could he not have sustained? could we not have sustained? could you not have sustained? could they not have sustained?	could I not have been sustaining? could you not have been sustaining? could he not have been sustaining? could we not have been sustaining? could you not have been sustaining? could they not have been sustaining?