为 + noun ＋ 所 + verb 为 indicates passive voice. Similarly, in English, "be .... by something/someone". 为 is equivalent to 被 in this situation. [ and only in this situation ] 为 is commonly used with 所, emphasizing the action relationship. They can be used to indicate precise description with minimum words, very compressed, saved a lot of paper and typing :) 为情所困 is quite commonly used in written/spoken Chinese and frequently used in lyric. 为情 -- by love affairs 所困 -- trapped, stepped in and cannot get out... It means someone cannot control their emotion ( being bad mood & unhappy ) due to love affairs. You can actually substitute any noun / verb phrases as you wish. 为noun/noun phrase 所 verb/verb phrase. But they're less common in modern Chinese, because it's actually not "Mandarin style". Chinese language have a very long history, and it is so rich in expressions. Some expressions we used nowadays is actually "ancient style". They are short, precise and compressed. No worries, we actually just use a very small portion of the language in our daily life. :) You will found it easy when you learn more. [it's over the word limit of a single post so I have to post 2 answers.]

Your Chinese is very good! We are discussing very precise descriptions in Chinese. [ Advanced level ] :) In your situation, 所, 为 are auxiliary-like words that indicate word "action relationships". Let's look at some examples below. 1. 他们并不领会王先生所说的话 ( They don't understand Mr. Wang's words / They don't grasp what Mr. Wang is saying ) Here, 所 "emphasize" the "worlds 话" are from Mr. Wang. What if the 所is omitted? 他们并不领会王先生说的话. That's actually very common, and the meaning is nearly the same as the first one, but with less emphasis on the action relationship. 2. 人所不能的，上帝都能 ( The God can do anything that human can not. ) The 所 here is a little-bit abstract and it's difficult to translate into English directly. Here, it's a kind of "substitution" as well. ( we do use 所 to substitute something/someone/somewhere) You can actually rewrite 人所不能的 with 人不能做的事, same meaning. 所 can be omitted, especially in spoken Chinese. 人不能的，上帝都能. It's still correct as 的 is a"substitution" of 的事. However, in written Chinese, we usually write the "full version". 人所不能的 人不能做的事 3. ... 所说的话... [ same as the first case ] ---------------------------------------------------------------------

所, 为 have different meaning with different combination. In your situation, they are 因为 - because of ... 所以 - and as a result =========================================================================== We can just omit either one actually, of course you can include both in a sentence. The usage is, 因为 + Reason description + 所以 + Result description Note: The description can be anything, we don't care if it is a noun / adjective / verb. ============================================================================ example, Noun + 所 + verb 路上发生了交通事故，所以我迟了回家。 Direct word by word translation: There is an car accident on the road, so I came home late. 路上- noun, On the road 发生了 - verb, occurred 交通事故 - noun, car accident 我 - noun & the subject, I 迟了 - adjective, late 回家 - verb + noun, 回go back/come back, 家-home Please note, verb in Chinese do not have tenses by itself, they are context dependent. 为 + noun ＋ 所 + verb 因为路上发生了交通事故，所以我迟了回家。 --> The meaning is just the same as the first sentence. ==================================================================

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