英文問題！句子分析

為方便解釋我的回答, 譲我將你的句子作成完整句子.
We should pay much more attention to our policies, that directly affect the corporation and, in turn, are affected by it (= corporation).
我們需要多加留意我們政策的制定, 因為政策和公司兩者是互相影響的.
1. 逗號的作用?
其實“in turn”係一句插入語 (parenthesis), 逗號正好顯示插入語的位置所在.
一句主句就正如樹木的主幹, 其分支就好似插入語, 逗號正好顯示分句的位置所在. (但當然, 並非所有逗號都顯示分句的位置啦!)
http://hk.dictionary.yahoo.com/search.html?s=parenthesis
【語】插入語句[C]
http://literaryzone.com/?p=203
Parenthesis is an explanatory word(s) that interrupts the grammatical flow of a sentence through brackets, commas or dashes.
插入語作用主要係解釋主句, 提供進一歩的資料.即使沒有這句插入語的存在, 主句在文法上是完整的. 但逗號的運用是有必要的, 這様可以界定它的存在是附加的.
More examples:
She told me, as she told everyone else, that she’s moving to Australia. (這裏「插入語」強調, 她也告訴其他人, 去清楚指出, 句中的我並不是唯一知情的人, 以避免一些誤會發生)
He came at night, at precisely 10:25, to ask for you. (這裏「插入語」準確地指出, 他曽在晩上10:25分正到達)
2. and的用法?
and係連接詞, 它的作用係將以下兩句連成一句.
a. Our policies directly affect the corporation. (policies係subject, 句子係active voice)
b. Our policies are affected by the corporation. (policies仍然係subject , 但句子係passive voice)
3. are 的作用?
雖然a和b句可以用and連接起來 (因為兩句的subject同様係Our policies), 但係兩句不同之處係, a句係active voice而b句係passive voice. 所以b句的are字係不可刪除.
以下的例子: 第二句的are字就可以刪除, 因為第一句己經有. (有相同的話, 就可以刪除後者)
Our policies are affected by the corporation.
Our policies are affected by the market.
=> Our policies are affected by both the corporation and the market.
4. 甚麼句式呢？
“that directly affect the corporation and, in turn, are affected by it”
這句是non-defining relative clause, 一句以”That”字為首的relative clause. 作用係修飾主句中的 policies. 但主句即使没有這句relative clause, 亦不會影響我們理解其意思. 相反, 如果没有這relative clause的幫忙就無法清楚了解其意思的話, 這句relative clause就稱為defining relative clause.
relative clause 亦可以用who/ whom/ which/ whose/ where等開頭.
http://www.ego4u.com/en/cram-up/grammar/relative-clauses#h05


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peace

2009-04-25 03:16:15 補充：
回答繼續

e.g. .Do you know the girl who is talking to Tom?

如果我們只係問Do you know the girl? 無人知道我們是指那一個 girl. (defining 意思係去界定「誰是這個女孩子」--- 即是正在跟Tom交談的那一位) . 這句relative clause連落主句時, 係不需用逗號 (在girl 和who之間), 因為這句relative clause是必須的, 並不是可有可無.

xxxxxx that directly affect the corporation and, in turn, are affected by it

in turn可解「跟着」或「反過來」。全句是: xxxxxx那會直接影響公司，和「反過來」(或「跟着」)被公司影響。

希望答到你的補問。

1只係一種表達方式,因為英文嘅習慣將重點擺最後,用逗號嚟起指印作用,句子a,b,c都係平排,都係咁重要,而將長句分到變短句,令意思簡單、直接、易明,同中文一樣.你唔+逗號都可以: xxxxxx that directly affect after the corporation and affected by it in turn.
2 前後兩句意思差唔多,主語一樣,用and做連接詞,冇and就要分兩句,因為冇主語,唔可以成為獨立嘅長句.
例: I eat an apple and an orange a day. I eat an apple a day. I eat an orange a day.
3 subject係xxxxxx,are跟佢,are affected係現在式嘅被動語態,即係有樣嘢 affects xxxxxx,但佢想強調影響(affect)公司(corporation),又俾佢影響(are affected by corporation).
4 因為睇唔到前面,你可以叫that-clause,即係用that嚟連接clause(短句)嘅句式.可以,文法正確,通常你想講同一樣嘢嘅好多個概念,都會用到,係正式嘅,口語都用得.