English verb conjugation
COULD LAST

Regular verb: last - lasted - lasted

Affirmation

Simple form	V-ing form
I could last you could last he could last we could last you could last they could last	I could be lasting you could be lasting he could be lasting we could be lasting you could be lasting they could be lasting
Perfect	V-ing perfect
I could have lasted you could have lasted he could have lasted we could have lasted you could have lasted they could have lasted	I could have been lasting you could have been lasting he could have been lasting we could have been lasting you could have been lasting they could have been lasting

Negation

Simple form	V-ing form
I could not last you could not last he could not last we could not last you could not last they could not last	I could not be lasting you could not be lasting he could not be lasting we could not be lasting you could not be lasting they could not be lasting
Perfect	V-ing perfect
I could not have lasted you could not have lasted he could not have lasted we could not have lasted you could not have lasted they could not have lasted	I could not have been lasting you could not have been lasting he could not have been lasting we could not have been lasting you could not have been lasting they could not have been lasting

Interrogative form

Simple form	V-ing form
could I last? could you last? could he last? could we last? could you last? could they last?	could I be lasting? could you be lasting? could he be lasting? could we be lasting? could you be lasting? could they be lasting?
Perfect	V-ing perfect
could I have lasted? could you have lasted? could he have lasted? could we have lasted? could you have lasted? could they have lasted?	could I have been lasting? could you have been lasting? could he have been lasting? could we have been lasting? could you have been lasting? could they have been lasting?

Interro-negative form

Simple form	V-ing form
could I not last? could you not last? could he not last? could we not last? could you not last? could they not last?	could I not be lasting? could you not be lasting? could he not be lasting? could we not be lasting? could you not be lasting? could they not be lasting?
Perfect	V-ing perfect
could I not have lasted? could you not have lasted? could he not have lasted? could we not have lasted? could you not have lasted? could they not have lasted?	could I not have been lasting? could you not have been lasting? could he not have been lasting? could we not have been lasting? could you not have been lasting? could they not have been lasting?