اخه لازم نــیس ک بدونی . . .
حالا ی چن تا مثال من میگم خودت میفهمی نیاز ب توضیح نداره !
He is interested in this music.
This is the kind of music in which he is interested.
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They are responsible for the accident.
Let's discuss the accident for which they are responsible.
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The books are on this table.
Can you see the table on which the books are?
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Putting the preposition before which is quite formal style.
In spoken English the preposition is usually at the end of the relative clause:
(ترجمه ی جمله ی بالا : گذاشتن حرف اضافه قبل which ی سبک کاملا رسمی است .
معمولادرانگلیسی گفتاری حرف اضافه درانتهای بندموصولی میاد )
This is the kind of music [which/that] he is interested in.
Let's discuss the accident [which/that] they are responsible for.
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البته ی چی هم درمورد in which بگم :
In the hospital there is an accident block where my friend was admitted’
In the hospital there is an accident blockin in which my friend was admitted <----
Thus, in which is used as an easy way to introduce a relative clause after a noun that refers to a place.
( ترجمه : بنابراین ؛ in which یک راه ساده است ک ی بند موصولی رو بعد ی اسم معرفی بکنه ک ب یه مکان اشاره بکند .)