Posterity is all the people who will be alive after you are dead — the future, not one child, not even just your family. When someone keeps a letter, a photo, or a building for posterity, they want people who are not born yet to see it. You hear it most in the set phrase for posterity.

Posterity is all the people who will be alive after you are deadPosterity（後世）指的是你死後還會活著的所有人 — the future, not one child, not even just your family——是未來，不是一個孩子，甚至不只是你的家人。 When someone keeps a letter, a photo, or a building for posterity當有人為了posterity保存一封信、一張照片，或一棟建築 , they want people who are not born yet to see it，他們是希望還沒出生的人也能看到它。 You hear it most in the set phrase你最常在這個固定用法裡聽到它 for posterity：for posterity（為了後世）。

It is a bookish, serious word. You would not use it when you chat about weekend plans.

It is a bookish, serious word它是一個書卷氣、嚴肅的字。 You would not use it你不會用它 when you chat about weekend plans來聊週末計畫。

Though actually, it is bigger than 子孫: your grandchildren are part of posterity, but so are strangers a hundred years from now.

Though actually不過其實 , it is bigger than 子孫，它比「子孫」的範圍還大 : your grandchildren are part of posterity：你的孫子是posterity的一部分 , but so are strangers a hundred years from now，但一百年後素不相識的陌生人也是。

It has nothing to do with a poster on the wall, and nothing to do with prosperity (being rich). Those only look a little like it.

It has nothing to do with a poster on the wall它跟牆上的poster（海報）沒有關係 , and nothing to do with prosperity (being rich)，也跟prosperity（有錢、繁榮）沒有關係。 Those only look a little like it那些字只是長得有點像而已。