1. Possessive apostrophes


Let’s start simple. For a singular noun, such as dog, you add an apostrophe plus s to the end: The dog’s collar was covered in mud.

For a plural noun, such as elephants, you add an apostrophe to the end: The elephants’ parade was stoped by rain.

For a plural noun that doesn’t end with s, you add an apostrophe plus s to the end: The children’s party went on as planned.

The place it gets tricky is with personal names, such as Charles and Ulysses, which already end in an s sound. In those cases, you generally add an apostrophe plus s if you naturally pronounce an extra s when you say the word out loud: Charles’s new tie is fantastic. If you don’t pronounce an extra s when you say the word, then leave it out: Ulysses’ presentation is set for Monday.

2. Semicolons

The central task of the semicolon is to mark a break that is stronger than a comma but not as final as a period or full stop. That sounds easy enough, but it can be hard to tell when you should be linking two clauses with a semicolon rather than simply separating them into two sentences.

Typically, you want to use a semicolon when two main clauses balance each other and are too closely linked to be made into separate sentences, as in these two examples:

The road runs through a beautiful wooded valley; the railway line follows it.

Erik did not give me your keys; he gave me mine.

You can also use a semicolon to mark a stronger division in a sentence that already has commas: The study showed the following: 76% of surveyed firms monitor employee Web-surfing activities, with 65% blocking access to unauthorized Internet locations; over one-third of the firms monitor employee computer keystrokes; half reported storing and reviewing employee emails; 57% monitor employee telephone conduct, including the inappropriate use of voicemail.

3. Colons

The best way to differentiate the colon from the semicolon is that where the semicolon provides a strong division in a sentence, the colon provides a sense of forward motion.

There are three main uses of the colon:

Between two main clauses in cases where the second clause explains or follows from the first, e.g. That is the secret to winning the game: have some patience.

Introducing a list, e.g. The film was criticized for several reasons: a weak script, stiff acting, and poor special effects.

Before a quotation, and sometimes direction speech, e.g. The poster read: Show is on 4 April’.

4. Hyphens

The principal purpose of the hyphen is linking words and parts of words. This means that it appears in a wide variety of situations, linking all types of words. Rather than pick out all of the possible appearances of the hyphen in everyday writing, we will focus on one that people frequently get wrong: compound adjectives.

Compound adjectives are made up of a noun + an adjective, a noun + a participle, or an adjective + a participle. Many compound adjectives should be hyphenated. For example,warm-hearted.

Compound adjectives get tricky once a phrase or the word well gets involved. In these cases, up-to-date and well-known, for instance, you should use a hyphen when the compound comes before the noun (up-to-date security system and well-known chiropractor), but not when the compound comes after (this software is up to date and this chimpanzee is well known). Similarly, centuries should be hyphenated when used as adjectives (She is one of the best twentieth-century writers) but not when used as a noun (These paintings date from the seventeenth century).

5. Dashes

The hyphen’s slightly longer cousin, the dash is another popular punctuation mark that not everyone is sure how to use.

In formal writing, the dash is used to mark off information or ideas that are not essential to an understanding of the rest of the sentence. For example, you might see: Once I have a free afternoon — I’ve been quite busy — I will meet you for lunch.
在正式的写作中,破折号用来划分信息和意见,而这些信息和意见对于理解句子不是很重要。例如,一旦我下午有时间—我一直很忙— 我就会和你吃午饭。

Even though dashes are common in informal writing, such as personal emails or blogs, it’s best to use them sparingly when writing formally.