A purifier is something used to take dirty or harmful substances out of air, water, or another material so it is cleaner. The ones students meet most are machines: an air purifier on a desk, a water purifier under the sink.

A purifier一個purifier is something used to take dirty or harmful substances out of air, water, or another material是用來把空氣、水，或其他物質裡的髒污或有害物質去除的東西，so it is cleaner讓它變得更乾淨。The ones students meet most學生最常碰到的 are machines是機器：an air purifier on a desk桌上的空氣清淨機，a water purifier under the sink水槽下的淨水器。

The word is simply “the thing that purifies.” It is a practical, shop-window word as much as a science word. A filter is often the part that does the work; people still call the whole machine a purifier.

The word這個詞 is simply就只是 'the thing that purifies'「用來淨化的東西」的意思。It這個詞 is a practical, shop-window word既是實用、商店櫥窗裡會用的詞，as much as a science word也同樣是科學用詞。A filter濾芯（filter） is often the part that does the work通常才是真正在做這件事的部分；people still call the whole machine a purifier但人們還是會把整台機器叫做purifier。

You can, more rarely, call a person a purifier if their job is to clean something, but the machine is the usual picture. It does not by itself tell you how well the thing works — only that cleaning is the claim.

You can可以，more rarely比較少見地，call a person a purifier把某個人叫做purifier if their job is to clean something如果他的工作就是清潔某樣東西的話，but the machine is the usual picture不過通常想到的還是機器。It這個詞本身 does not by itself tell you how well the thing works並不會告訴你這東西效果好不好——only that cleaning is the claim只表示「清潔」是它宣稱要做的事。