GUMP
You need to know, understand, and command the following GUMP items in your writing:
1) Five uses of the comma: 1) after introductory elements; 2) before and after interrupting elements; 3) to separate items (nouns, verbs, or phrases) in a series; 4) before a direct quotation; 5) and to separate two independent clauses connected by FANBOYS
2) Two uses of the semi-colon: 1) to separate two independent related clauses (as in John is a star on the basketball team; Jeff is the best wrestler); 2) to separate items in a series where there is already a comma as in the following: AFS has several wonderful athletes who have starred in sports: John, in basketball; Justin, in swimming; and Hannah, in softball.
3) Two uses of the colon: 1) to separate items in a series after a complete sentence as in the following: AFS has several wonderful athletes who have starred in sports: John, in basketball; Justin, in swimming; and Hannah, in softball. 2) And in the salutation of a formal letter as in Dear Director:
4) Run-ons or fused sentences: Run-ons have at least two parts, either one of which can stand by itself (in other words, two independent clauses), but the two parts have been smooshed together instead of being properly connected.
It is important to realize that the length of a sentence really has nothing to do with whether a sentence is a run-on or not; being a run-on is a structural flaw that can plague even a very short sentence:
The sun is high, put on some sunblock.
An extremely long sentence, on the other hand, might be a "run-off-at-the-mouth" sentence, but it can be otherwise sound, structurally. What follows is NOT a run-on sentence:
Knowing that millions of people around the world would be watching in person and on television and expecting great things from him — at least one more gold medal for America, if not another world record — during this, his fourth and surely his last appearance in the World Olympics, and realizing that his legs could no longer carry him down the runway with the same blazing speed and confidence in making a huge, eye-popping leap that they were capable of a few years ago when he set world records in the 100-meter dash and in the 400-meter relay and won a silver medal in the long jump, the renowned sprinter and track-and-field personality Carl Lewis, who had known pressure from fans and media before but never, even as a professional runner, this kind of pressure, made only a few appearances in races during the few months before the Summer Olympics in Atlanta, Georgia, partly because he was afraid of raising expectations even higher and he did not want to be distracted by interviews and adoring fans who would follow him into stores and restaurants demanding autographs and photo-opportunities, but mostly because he wanted to conserve his energies and concentrate, like a martial arts expert, on the job at hand: winning his favorite competition, the long jump, and bringing home another Gold Medal for the United States, the most fitting conclusion to his brilliant career in track and field.
5) Comma splices: When two independent clauses are connected by only a comma, they constitute a run-on sentence that is called a comma-splice. The example just above (The sun is high, put on some sunblock) is a comma-splice. When you use a comma to connect two independent clauses, it must be accompanied by a little conjunction (and, but, for, nor, yet, or, so).
6) The difference between it’s and its: it’s is a contraction for it is; its shows possession (as in China changed its trade policy; the U.S. responded with restrictions of its own.)
7) The difference between your and you’re and their and they’re. See above. Your is the possessive. You’re means you are. There should be no confusion between the two. Ditto. They’re, their, and there.
8) Titles: Titles of books, movies, TV shows, websites, and articles in books take different punctuation. When you write a title, you need to punctuate it correctly. Use Big Dog or other site.
9) Agreement of indefinite pronouns: With subject-verb agreement, we also talked about indefinite pronouns ("-one," "-body," and "-thing" words). With pronouns, we need to look at the "-one" and "-body" words again. (Also include "either," "neither," and "each.") These are always singular, and that should be easy enough to remember. But most beginning writers seem to have trouble with them. Part of the problem is the way we speak. Few would notice anything wrong if they heard someone say,
o Everyone needs to take their dog to the vet regularly.
o Everybody was enjoying their vacation.
These sound okay, right? Maybe so, but they're wrong if you're writing. Words like "everyone" and "everybody" are always singular, so the plural pronoun their can't agree with them. The correct versions are:
o Everyone needs to take his dog to the vet regularly.
o Everybody was enjoying her vacation.
You could use his or her in either sentence, depending upon the context.
10) Uses of the apostrophe: to show possession and to indicate a missing letter or letters as in the following: Chip’s bicycle; don’t.