A bystander is someone who is there when something happens and watches, but does not take part. The word is ordinary English, and news stories use it a lot: an innocent bystander got hurt; bystanders filmed the fight.

A bystander isBystander 指的是 someone who is there when something happens and watches事情發生時人在現場、在旁邊看的人，but does not take part但沒有參與。The word is ordinary English這個字是很普通的英文，and news stories use it a lot新聞報導很常用：an innocent bystander got hurt無辜的旁觀者受傷；bystanders filmed the fight旁觀者把打架的過程拍了下來。

It is not a job, and it is not a very formal word.

It is not a job它不是一種職業，and it is not a very formal word也不是很正式的字。

People also talk about the bystander effect — the sad idea that when many people are watching, each person waits for someone else to help.

People also talk about人們也會談到 the bystander effectbystander effect（旁觀者效應）——the sad idea that一個令人難過的現象：when many people are watching當很多人在看的時候，each person waits for someone else to help每個人都在等別人出手幫忙。

A witness is a bit different: a witness is someone who saw it and may later tell the story, especially to the police. A bystander may become a witness, but the first word only says they stood to the side.

A witness is a bit differentwitness（目擊者）有點不一樣：a witness iswitness 指的是 someone who saw it and may later tell the story看到事情發生、之後可能要把經過講出來的人，especially to the police尤其是講給警察聽。A bystander may become a witnessBystander 可能會變成 witness，but the first word only says但 bystander 這個字本身只是說 they stood to the side他們站在旁邊而已。