https://gmat.economist.com
The Economist上有一個有關GMAT的博客 -- GMAT Tutor Blog, 其中有一篇文章討論了like和as的使用:
以下為文章原文節選, 加粗等標記還有中文補充是我後加的:
Most people hear and use the word 「like」 more pervasively than many other words in the English language. When it comes to the GMAT (sentence correction, in particular), the difference between like and as in a sentence is subtle enough to make it difficult to complete an otherwise straightforward sentence.
However, there isn’t quite as complicated a strategy to decide between these two words as you might be thinking. In fact, understanding the differences only requires a more intimate understanding of what type of word each one is. To help you tackle the tricky decision between like and as, we』ll actually take a step back and review the differences between a preposition and a conjunction.
English Vocabulary in Use 一書中提到認識一個單詞，不僅要知道這個詞什麼意思，還要注意這個詞能怎麼搭配使用，和這個詞有關的詞有什麼，這個單詞的語法特點是什麼 -- 詞性(part of speech)還有具體的用法。很多時候我們用錯一個詞，就是因為我們忽略了它最基本的特徵，才想當然的使用。例如like和as在某些句子中的用法區別，就是詞性的不同 -- 一個是preposition, 一個是conjunction
The difference between a preposition and a conjunctionChoosing between like and as on a sentence correction question becomes much easier when you understand the difference between a preposition and a conjunction. You』ll see in the definitions of each below that while they are not too different in nature, the subtle differences between both will point you towards the right answer choice on test day.
A preposition is a word that positions words in relation to one another, typically used when the following word is not a verb. Like would fall into this category, as well as words like 「in,」 「around」 and 「through.」
A conjunction is a more simple connecting word— it can connect everything from full sentences to individual words and does not itself define the relationship between the two items it connects (which prepositions such as 『around』, 『above』, and 『like』 do). Other conjunctions include 『and』, 『but』, 『so,』 etc.
更具體的解釋和使用請訪問原文:
https://gmat.economist.com/blog/verbal/vs-do-you-know-difference-between-two
今天和大家分享的是在比較句中，than後面用主格還是用賓格, 例如這樣一個句子:
Eric is taller than I am.
你或許見過以下兩個版本:
1. Eric is taller than I.
2. Eric is taller than me.
簡單的說，這兩個版本都是正確的，主要的區別是than這個詞到底是conjunction(如1), 還是preposition(如2)? -- 這個爭論已經持續了幾百年！我一直推薦的Grammar Girl在其博客回答了這個問題，原文請點擊閱讀原文閱讀, 在此只是節選。
So the battle continues: the conjunctionists have history and the avoidance of ambiguity on their side, while the prepositionists have than whom and several counterexamples on theirs. Who wins? I believe Ken Wilson sums it up best in The Columbia Guide to Standard American English (3):
Than is both a subordinating conjunction, as in She is wiser than I am, and a preposition, as in She is wiser than me.... Since the following verb am is often dropped or 「understood,」 we regularly hear than I and than me. Some commentators believe that the conjunction is currently more frequent than the preposition, but both are unquestionably Standard.
So remember, than he and than him are both defensible, but not all grammar mavens feel this way. Therefore, I would avoid the prepositional use in formal settings, such as a research paper or job interview—and I would argue, advertising, but Cadbury obviously feels otherwise. The usage note in The American Heritage Dictionary (4) agrees: 「The writer who risks a sentence like Mary is taller than him in formal writing must be prepared to defend the usage against objections of critics.」 Unfortunately, defending your grammar during an interview is not the best way to make a good impression.
The quick and dirty tip to determining which pronoun is appropriate after the conjunction than is to figure out the pronoun’s role in the implied sentence by mentally filling in the missing words. Are you trying to say Aardvark likes Squiggly more than I [like Squiggly] or Aardvark likes Squiggly more than [Aardvark likes] me? Sometimes, even if you use the correct pronoun, you may find sentences like I'm taller than he sound too formal in casual setting. If so, you can use a verb to complete the implied sentence, saying instead, I'm taller than he is. With a verb present, the choice is obvious: subject pronouns are the only option. After all, both sides of the than he/than him debate agree that No bunny knows Easter better than he does.
另一篇文章裡也提到了使用than me容易產生的ambiguity，以及than whom的用法:
http://www.grammar-monster.com/lessons/than_I_me_than_he_him.htm
一個萬全之策就是把話說完整 -- "The safest option is to expand the words after than. This usually means adding at least the verb (e.g., than he is / than they have). This removes all ambiguity and stops your wording sounding pretentious." 例如上面的例句可以寫為John likes Peter more than I do.
把這篇文章中提到的連結都看一遍，應該就清楚了。不懂得問題就多搜一搜, 注意參考內容是否具有一定的權威性, 要有基本的辨別和篩選能力，這種能力就是在一次一次的「探索」中提高的。
不定冠詞倒置
從雙重否定看英文語法
什麼時候你不需要that THAT
比單詞量和語法更重要的是