I could endure you could endure he could endure we could endure you could endure they could endure
V-ing form
I could be enduring you could be enduring he could be enduring we could be enduring you could be enduring they could be enduring
Perfect
I could have endured you could have endured he could have endured we could have endured you could have endured they could have endured
V-ing perfect
I could have been enduring you could have been enduring he could have been enduring we could have been enduring you could have been enduring they could have been enduring
Negation
Simple form
I could not endure you could not endure he could not endure we could not endure you could not endure they could not endure
V-ing form
I could not be enduring you could not be enduring he could not be enduring we could not be enduring you could not be enduring they could not be enduring
Perfect
I could not have endured you could not have endured he could not have endured we could not have endured you could not have endured they could not have endured
V-ing perfect
I could not have been enduring you could not have been enduring he could not have been enduring we could not have been enduring you could not have been enduring they could not have been enduring
Interrogative form
Simple form
could I endure? could you endure? could he endure? could we endure? could you endure? could they endure?
V-ing form
could I be enduring? could you be enduring? could he be enduring? could we be enduring? could you be enduring? could they be enduring?
Perfect
could I have endured? could you have endured? could he have endured? could we have endured? could you have endured? could they have endured?
V-ing perfect
could I have been enduring? could you have been enduring? could he have been enduring? could we have been enduring? could you have been enduring? could they have been enduring?
Interro-negative form
Simple form
could I not endure? could you not endure? could he not endure? could we not endure? could you not endure? could they not endure?
V-ing form
could I not be enduring? could you not be enduring? could he not be enduring? could we not be enduring? could you not be enduring? could they not be enduring?
Perfect
could I not have endured? could you not have endured? could he not have endured? could we not have endured? could you not have endured? could they not have endured?
V-ing perfect
could I not have been enduring? could you not have been enduring? could he not have been enduring? could we not have been enduring? could you not have been enduring? could they not have been enduring?