Needful means necessary — something you must have or must do. The pieces are plain: need + -ful.

NeedfulNeedful means意思是 necessary必要的 something you must have or must do你必須擁有或必須做的東西 The pieces are plain拆開來很簡單 need + -fulneed 加上 -ful

Though actually, most English speakers today do not reach for this word in ordinary talk. They say needed or necessary instead.

Though actually不過實際上 most English speakers today今天大部分說英語的人 do not reach for this word不會用這個字 in ordinary talk在日常對話裡 They say instead他們會改說 needed or necessaryneeded 或 necessary

You will still meet it in older books, in church language, and in a few set phrases.

You will still meet it你仍然會遇到它 in older books在較老的書裡 in church language在教會用語裡 and in a few set phrases還有一些固定說法裡

In Indian English, “please do the needful” is a normal, polite way to ask someone to do what the situation requires. In British and American English that same sentence can sound stiff, old, or even a little funny, as if the speaker had copied a form letter.

In Indian English在印度英語裡 "please do the needful"「please do the needful」 is a normal, polite way是很正常、有禮貌的說法 to ask someone to do what the situation requires用來請人做情況需要的事 In British and American English在英式和美式英語裡 that same sentence同樣這句話 can sound stiff, old, or even a little funny可能聽起來生硬、老派，甚至有點好笑 as if the speaker had copied a form letter好像講話的人是照抄公文範本一樣

There is also an old slang use of the needful for money, but you are unlikely to hear it now.

There is also an old slang use也有一個舊時的俚語用法 of the needful for money用 the needful 指錢 but you are unlikely to hear it now但你現在不太可能聽到了