1. To join two independent clauses, use a comma followed by a conjunction, a semicolon alone, or a semicolon followed by a sentence modifier. (来源：最老牌的英语学习网站 http://www.EnglishCN.com)

　　2. Use commas to bracket nonrestrictive phrases, which are not essential to the sentence's meaning.

　　3. Do not use commas to bracket phrases that are essential to a sentence's meaning.

　　4. When beginning a sentence with an introductory phrase, include a comma.

　　5. To indicate possession, end a singular noun with an apostrophe followed by an 's'. Otherwise, the noun's form seems plural.

　　6. Use proper punctuation to integrate a quotation into a sentence. If the introductory material is an independent clause, add the quotation after a colon. If the introductory material ends in 'thinks,' 'saying,' or some other verb indicating expression, use a comma.

　　7. Make the subject and verb agree with each other, not with a word that comes between them.

　　8. Be sure that a pronoun, a participial phrase, or an appositive refers clearly to the proper subject.

　　9. Use parallel construction to make a strong point and create a smooth flow.

　　10. Use the active voice unless you specifically need to use the passive.

　　11. Omit unnecessary words.