1. which 用法
which 係英文文法入面屬於關係代名詞(relative pronoun)， 指稱「一件事/物件」，例子有﹕
I don’t know which pen is yours (我唔知邊支筆係你嘅)
係呢種情況下，which 就係指果枝屬於你嘅筆。
which亦可以用作連接兩句句子，從而對該「事/物件」作出更多描述，例如﹕
Apple was founded by Steve Jobs (Apple由Steve Jobs 創辦)
+
Apple has changed the world. (Apple改變左呢個世界)
=
Apple, which was founded by Steve Jobs, has changed the world. (由steve jobs 創辦嘅Apple改變左呢個世界)
記住，which 一定係跟係noun後面!知道左which嘅基本用法同意思之後，我地就可以睇下which 前面加上唔同介詞係咩意思啦! 首先睇下in which﹕
2. in which 用法及中文意思
1. in whcih 可以理解為將句子後面嘅介詞(preposition，即係in/ of/ on 等)搬到前面，從而令句子變得更加正式，例子有﹕
I grew up in this neighborhood.
+
This neighborhood has been rebuilt.
=
This is the neighborhood in which I grew up has been rebuilt.= This is the neighborhood which I grew up in has been rebuilt (我細個住果區已經重建左啦)
2. 形容「地點」
與此同時，當which係用黎形容事物嘅時候，in which 就係用黎形容「地點」，將兩句句子連接埋一齊， 同時亦可以用where代替，但in which 就有比較強調「係..入面」嘅意思，例如﹕
I once studied in this university
+
this university is the best one in HK.
=
This is the university where I once studied is the best one in HK= This is the university in which I once studied is the best one in HK (強調佢係呢間大學入面讀過)
記得，如果係想用where去取代in which嘅話，就要連埋個preposition(即係in)都拎走埋!
3. of which 用法
1. 介詞前置
of which嘅用法同原理亦同in which相似，首先同樣係介詞前置嘅用法﹕
Jane is now working in a company.
+
You must have heard of this company.
=
Jane is now working in a company which you must have heard of. = Jane is now working in a company of which you must have heard. (Jane而家做緊嘅公司你一定都聽過)
2. of which 嘅另外一個意思係「其中」。
當of which係用黎連接兩句句子嘅時候，of which 跟住果句就係形容緊前句嘅其中一樣野，例如﹕
前句﹕There are 3 pens on the desk
+
後句﹕The pen in red is mine
=
There are 3 pens on the desk, of which the pen in red is mine.（枱面有3枝筆，其中紅色果枝筆係我嘅）
係呢個例子入面，of which 後面嘅 ’the pen in red’ 就係講緊枱面上3枝筆嘅其中一枝
4. by which 用法
- 介詞前置
同樣是介詞前置的原理，請看以下例子﹕
He was known by a nickname at school.
+
His nickname is ‘Spiderman’
=
The name by which he was known at school is Spiderman.（他以「蜘蛛人」的綽號在學校內非常有名）
2. by which 的另外一個意思是「藉由…」，
當by which用以連接兩句句子時，前句就是後句「動作」的結果，例如﹕
前句﹕He learns English in many ways.
+
後句﹕He takes online English courses to practice his oral English.
=
One of the ways by which he learns English is taking online English courses to practice his oral English. （他其中一個學英文的方法是藉由線上英語課程練習英語會話）
關於which嘅更多特殊用法，可以參考以下短片﹕
實戰練習考考你(答案係網頁最下方)﹕
- The book is sold out + The book is written by JinYoun = ?
- I keep all my books in the box + The box was bought from LogOn = ?
- Harry Potter has been translated into over 80 languages + The English version of Harry Potter is the most popular and original one = ?
- There are 365 days in a year + My favourite day of the year is my birthday = ?
- 邊度有錯? Hong Kong is a crowded city where more than 7 millions people live in
5. at which, on which, for which 用法及意思
同in which/ of which一樣，基本上所有「介詞+which」嘅第一個用法都係介詞前置，即係將後句最後嘅介詞放係which 前面。
而意思上就每個字都有不同嘅意思，用法亦大同小異，同樣係用後句形容前句，其中包括﹕
at which = 「係…某一點上」
The picture at which everybody is starring was painted by Da Vinci. (果幅人人都望緊嘅畫係達文西嘅作品)
for which = 「為左….」
I will buy you the reference book for which you asked (我會買你講過果本參考書比你)
on which =「係..上面」
You can take my key from my desk on which there are many photos.(你可以去我張枱度拎我條鎖匙，我張枱上面有好多相)
基本上，「介詞+which」最後出黎嘅意思同介詞本身嘅意思有好大關係；關於每個介詞嘅詳細用法，可以參考以下文章﹕
6. who/ whom用法
同which類似嘅relative pronoun仲有who/whom, 不過指嘅係人而唔係事物。當你指嘅人係句子嘅subject時用who指稱，如果係object就用whom指稱，例如﹕
He is a teacher
+
He teaches English online
=
He is a teacher who teaches English online.
係呢句入面，’He’係成句野嘅主語，所以係用who。又例如﹕
He loves the teacher very much
+
The teacher teaches English on AmazingTalker
=
He loves the teacher whom teaches English on AmazingTalker
係呢句入面，’He’係主語，’teacher’係object，而後句係形容緊teacher，所以中間係用whom而唔係who
Ans:
1. The book which is sold out is written by JinYoun
2. The box in which I keep all my book was bought from LogOn.
3. Harry Potter has been translated into over 80 languages, of which the english version is the most popular and original one.
4. There are 365 days in a year, of which my favourite is my birthday.
5. 最尾多左個’in’, 用where嘅話要拎走埋preposition，你亦可以寫Hong Kong is a crowded city in which more than 7 millions people live
搞清楚in which的用法了嗎?基本上，「介詞+which」最後出來的意思與介詞本身的意思有很大的關係；關於每個介詞的詳細用法以及更多的英文文法入門攻略，可以參考以下文章﹕
使役動詞怎麼用才對? make、have、let、get用法
最後， 歡迎點讚我們的英文學習專頁和加入我們的Whatsapp英文學習群組，上面會不定期發放英文學習的資訊和攻略喔！
