1. Grammar & Punctuation Analysis
Sentences taken from Ch 7 in Outliers

2. Twenty years before the crash of KAL 801, a Korean Air Boeing 707 wandered into Russian airspace and was shot down by a Soviet military jet over the Barents Sea.
Why is there a comma after KAL 801?
Why is there no comma after airspace?

3. In short order, the US Army, which maintains thousands of troops in South Korea, forbade its personnel from flying with the airline.
Is the comma after order necessary? Why or why not?
Why is which maintains thousands of troops in South Korea set off by commas?

4. By the time of the Shanghai crash, the Korean president, Kim Dae-jung, felt compelled to speak up.
Why is there a need for a comma after crash?
Why do we set off Kim Dae-jung with commas?

5. It took less than a day for the cause of the crash to be determined: “fuel exhaustion.”
Notice that the end punctuation (the period) is placed inside the closing quotation mark, not outside (…exhaustion”.)

6. “It’s a classic case,” said Suren Ratwatte, a veteran pilot who has been involved for years in “human factors” research, which is the analysis of how human beings interact with complex systems like nuclear power plants and airplanes.
Why use it’s rather than its?
Note the comma before the closing quotation mark after case
Why is a comma needed after Ratwatte?
Why is a comma needed after research?

7. “At that stage, I took over the controls,” he went on
“At that stage, I took over the controls,” he went on. “I had to ensure that the airplane touched down very softly; otherwise, there would have been a risk of structural damage…”
Do we really need the comma after stage?
Note the placement of the comma after controls
Why use a semi-colon and a comma instead of 2 commas to set off otherwise?

8. Danes look a lot like Belgians, and if you were dropped on a street corner in Copenhagen, you wouldn’t find it all that different from a street corner in Brussels.
Are the commas used to set off and if you were dropped on a street corner in Copenhagen, or are they each used for two separate reasons?
The reasons?