Common Mistakes..

Common sentence structure mistakes

• Periods and commas should always go inside quotation marks. For example: "Write like this," she said. Question marks and exclamation points can go inside or outside the quotation marks, depending on whether they are part of the material being quoted. Please note that this is the American method, British English places all following punctuation after the quotation marks. See the Wikipedia page on British and American English usage for more information.

• Use square brackets within parentheses when you must use parentheses again (i.e., "She spoke ironically [meaning jokingly]").

• Use a semicolon in the place of a period when joining two sentences that share a central idea. For example, "Many people think that semicolons should be used the same way as commas; they should not be."

• Use either an em dash (—) or en dash(–) instead of "-" or "--". This depends, however, on the typesetting system available.

• Apostrophes should be used only for contractions ("It's OK to use one here") or possessive form ("Bob's use of apostrophes is correct"), with few exceptions. It is incorrect to use an apostrophe to indicate a plural ("Error's like this are annoying").

• Do not use constructions such as "as good or better than," because "as good than" makes no sense by itself. If you must use this phrasing, it should be "as good as or better than," because then each part stands on its own. A more graceful phrasing is "at least as good as."

FRom: Wikipedia