雷哥GMAT视频课程之GMAT语法知识点 MOST IMPORTANTLY PUNCTUATION IS NOT TESTED ON THIS EXAM! don't bother with “rules” based on punctuation, because (a) gmac doesn't test them, and, more importantly, (b) the vast majority of them will not actually be real rules. the only time you'll want to mind punctuation, at all, is when it actually differentiates grammatical structures: for instance, “no comma + -ing” is different from “comma + -ing”. but, those kinds of things aren't really punctuation issues -- they are issues concerning the resulting structures. for instance, the example i just mentioned would be a modifier issue, not a punctuation issue. -- regarding this whole belief that comma + and/but/etc MUST introduce another independent clause: well, not really. this “rule” is not really a rule. it's an approximate guideline in most cases, but it's definitely not a strict rule. * quite often, the comma will be omitted when there are two complete clauses -- if those clauses are short enough to render the comma unnecessary. since the doors are locked and the windows are latched, we're ready to go. --> this is fine; there's no reason to separate "the doors are locked" and "the windows are latched" with a comma. indeed, the sentence would be a lot more confusing if you did that. * also -- again quite often -- a comma will be included even if the structures are not complete clauses, especially if the structures are long enough to make the sentence unreadable without the comma. for instance: i shut the windows and locked the doors --> this sentence doesn't need any additional punctuation. i shut the windows so firmly that i would later have trouble opening them, and locked the doors using both the standard locks and the deadbolts --> these are not complete clauses, but the sentence is still written with the comma because it's absolutely unreadable without the comma. (try it yourself.) again, this is all of marginal importance, because punctuation is Something You Just Don't Have To Worry About on this exam. that should be good news, considering the number of things you do have to worry about. if comma + AND is followed by a complete sentence ("independent clause"), then the clauses before and after AND should make sense as parallel statements. e.g. stephanie told me that her son was sick and she would need an extra day to finish the project. --> this sentence makes sense, with "her son was sick" and "she would need an extra day..." in parallel. stephanie told me that her son was sick, and she would need an extra day to finish the project. --> this sentence doesn't make sense. the comma construction implies that "stephanie told me that her son was sick" and "she would need an extra day to finish the project" are separate and parallel. that interpretation doesn't make sense; the sensible interpretation of the sentence is that stephanie told me both things, but, according to this parallelism (in which the two sentences are separate ideas), stephanie only told me thing #1.[/b] 本文来源:https://www.wddqw.com/doc/7e55417e6c85ec3a87c2c5dd.html