Could vs Would
Could
= 1) Past tense of “can”
= 2)Used to show possibility
Ex: You could be right about that.
= 3) Used in making polite requests
Ex: Could I use your bathroom?
Would
= 1) Past tense for “will”.
Ex: He would work for many years until he died.)
= 2)Used to express the future in past sentences
Ex: He said he would go tomorrow)
= 3) Used to show the consequence of an imagined event or situation
Ex: He would lose his job, if he didn’t go to work.)
= 4) Giving advice
Ex: I would go to work, if I was you.)