The advisers at CWAC often find questions about grammar and style that do not have one clear solution. Sometimes, several style guides will offer differing explanations or justifications for certain writing rules. Frustrated, the CWAC advisers have begun solidifying and compiling straight-forward responses to a few of these uncertainties. This is a work-in-progress, and more tips will be added periodically.
When using the apostrophe to indicate possesion with singular nouns ending in -s, the rule is to use 's. For example, "Uncle Charles's favorite pair of shoes."
The exception to this rule is when indicating possession with "ancient" names ending in -s, such as "Aquarious," "Jesus," and "Odysseus." For example, "Aquarious' house was well-maintained."
What to do when connecting two independent clauses with a comma + cooridnating conjunction, followed immediately after by a nonessential element:
Normally, nonessential elements are set-off from the main sentence with commas, such as "My Uncle Charles, a short man with half-moon glasses, loves to wear loafers."
However, when the nonessential element follows a comma + cooridnating conjunction (for, and, nor, but, or, so, yet), the nonessential element is only followed, and not preceeded by, a comma. For example, "My family often goes skiing on vacation, and even when the weather is harsh, we enjoy being active and exploring the outdoors."
Source: Strunk, William, and E.B. White. The Elements of Style. 4th Ed. Needham Heights: Allyn & Bacon, 2000. Print.