(完整word版)定語從句as的用法 as 引導(dǎo)定于從句： 1、as用作關(guān)系代詞和關(guān)系副詞引導(dǎo)限定性定語從句，并在從句中做主語、表語和狀語，構(gòu)成the same ...as, such。..as等結(jié)構(gòu)。 Eg: I have got into the same trouble as you. 2、 as引出非限定性定語從句時，代替整個主句，對其進(jìn)行說明。但通常用于:（as we all know， as it is known, as is known to all， as it is, as is said above, as always mentioned above, as is usual, as is often the case, as is reported in the newspaper） . as在非限定性定語從句中作主語、表語或賓語，且引出的從句位置比較靈活，可位于句首或句末，也可置于主句中間。通常均由逗號將其與主句隔開。 as有“正如……， 就像……"之意. Eg: As is known to the United States, Mark Twain is a great American writer。 美國人都知道，馬克·吐溫是一位偉大的美國作家（as在從句中作主語） He forgot to bring his pen with him, as was often the case. 他忘了帶筆，這是常事。（as在從句中作主語） He is absorbed in work, as he often was. 他正在全神貫注地工作，他過去經(jīng)常這樣.（as在從句中作表語） As we all know, the earth is round. 眾所周知，地球是圓的。(as在從句中作賓語） The two brothers were satisfied with this decision, as was agreed beforehand. 兩兄弟對此決定都滿意,這項決定在事前都已得到他們的同意.（as在從句中作主語） Taiwan is，as you know，an inseparable part of China. 你知道，臺灣是中國不可分割的一部分。(as在從句中作賓語） 注意：which引導(dǎo)的非限制性定語從句只能放在主句之后。 Eg: He hse been to Paris more than several times, which I don't believe. as 引導(dǎo)非限制性定語從句時與which的區(qū)別: ①當(dāng)主句和從句語義一致時，用as；反之,用which來引導(dǎo)非限制性定語從句。 e.g。 He made a long speech， as we expected. He made a long speech， which was unexpected. ②當(dāng)非限制定語從句為否定時,常用which引導(dǎo)。 e。g。 Tom drinks a lot every day， which his wife doesn’t like at all.