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 couldn't sustain you couldn't sustain he couldn't sustain we couldn't sustain you couldn't sustain they couldn't sustain	I couldn't be sustaining you couldn't be sustaining he couldn't be sustaining we couldn't be sustaining you couldn't be sustaining they couldn't be sustaining
Perfecto	Perfecto con V-ing
I couldn't have sustained you couldn't have sustained he couldn't have sustained we couldn't have sustained you couldn't have sustained they couldn't have sustained	I couldn't have been sustaining you couldn't have been sustaining he couldn't have been sustaining we couldn't have been sustaining you couldn't have been sustaining they couldn't 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
couldn't I sustain? couldn't you sustain? couldn't he sustain? couldn't we sustain? couldn't you sustain? couldn't they sustain?	couldn't I be sustaining? couldn't you be sustaining? couldn't he be sustaining? couldn't we be sustaining? couldn't you be sustaining? couldn't they be sustaining?
Perfecto	Perfecto con V-ing
couldn't I have sustained? couldn't you have sustained? couldn't he have sustained? couldn't we have sustained? couldn't you have sustained? couldn't they have sustained?	couldn't I have been sustaining? couldn't you have been sustaining? couldn't he have been sustaining? couldn't we have been sustaining? couldn't you have been sustaining? couldn't they have been sustaining?