Question 1

What is the difference between a hyphen and a dash?

Accepted Answer

A hyphen is short, has no spaces, and joins words into one: twenty-one, mother-in-law, a well-known singer. A dash is longer and breaks a sentence to add, interrupt or emphasise: We had one visitor — Nani. (That line is an em dash.) So ask whether the line joins words or breaks the sentence open. Join means a hyphen; break means a dash.

Question 2

Do you put a hyphen in twenty-one?

Accepted Answer

Yes. Every two-part number from twenty-one to ninety-nine takes a hyphen when it is written in words: twenty-one, forty-five, ninety-nine. Round tens stay single words: twenty, sixty. In bigger numbers only the last two-part piece is joined: one hundred and twenty-six. Twenty one, with a space, is a slip in every style.

Question 3

Is it seven-year-old or seven years old?

Accepted Answer

Both, in different places. Before a noun, the age is one describing idea, so it is joined: a seven-year-old girl. Used as a noun it is joined too: the seven-year-olds. After the verb it is an ordinary phrase with no hyphens: She is seven years old. When joined, year stays singular: never a seven-years-old girl.

Question 4

When do you hyphenate a compound adjective?

Accepted Answer

When two or more words work together as one describing idea before a noun: a well-known singer, a part-time job, a five-star hotel, a 100-metre race. The hyphen stops the reader taking the first word on its own. Words a dictionary always hyphenates keep the hyphen anywhere, but most pairs open up after the verb: the job is part time.

Question 5

Is it well-known or well known?

Accepted Answer

Before a noun, well-known: a well-known singer. After the verb, Chicago and the usual school pattern open it: The singer is well known. Some British writing keeps the hyphen after the verb too, and that is standard where it is used. Compounds a dictionary lists with a hyphen, such as good-looking and old-fashioned, keep it everywhere: She is good-looking.

Question 6

Do you hyphenate adverbs ending in -ly?

Accepted Answer

No. An adverb ending in -ly already shows that it describes the next word, so no hyphen is needed: a quickly written note, a brightly lit room, a newly built bridge. Watch for words that end in -ly but are not adverbs, such as friendly and family. Those can take a hyphen before a noun: a friendly-looking dog, a family-sized pack.

Question 7

Do fractions like two-thirds need a hyphen?

Accepted Answer

When a fraction describes a noun, yes: a two-thirds majority, a one-third share. When the fraction is the amount itself, styles differ. Two-thirds of the class passed and Two thirds of the class passed are both standard, depending on the dictionary or house style you follow. Choose one form and keep it through the whole piece.

Question 8

Do prefixes like re-, pre- and un- need a hyphen?

Accepted Answer

Usually not. Most prefixes join straight on: rewrite, preview, unhappy, antibiotic, postwar. A hyphen comes in when the next part starts with a capital letter or a number: un-Indian, anti-British, pre-1947, mid-July. It also helps where two vowels meet or the meaning would change: re-enter, re-cover a sofa. So write rewrite, not re-write.

Question 9

Do you hyphenate ex-, self- and all-?

Accepted Answer

Yes, in most styles. These prefixes keep a hyphen: ex-captain, ex-student, self-respect, self-control, all-round, all-India. Here ex- means former. Selfish and selfless have no hyphen, because -ish and -less are endings added to the word self, not the prefix. Write ex-captain, not excaptain, and self-respect, not self respect.

Question 10

How do you use dashes in the middle of a sentence?

Accepted Answer

Use a pair round extra information, one before it and one after: My cousin — the one in Pune — is visiting. (Those are em dashes.) The sentence must still work if you lift out the words between them: My cousin is visiting. Close the aside with a dash, never a comma. Commas or brackets can do the same job more quietly.

Question 11

What is the difference between an en dash and an em dash?

Accepted Answer

The en dash (–), about as wide as an n, means to or between: pages 10–25, the Delhi–Mumbai train. The em dash (—), about as wide as an m, breaks a sentence: There was one thing to do — run. British publishing often uses a spaced en dash for that break. Phones often use a hyphen for both.

Question 12

Should a dash have spaces around it?

Accepted Answer

It depends on the house style; all three are standard. Most British publishing uses a spaced en dash: My cousin – the one in Pune – is here. Most American books, following Chicago, APA or MLA, use a closed em dash: My cousin—the one in Pune—is here. AP news style uses an em dash with spaces. Pick one and keep it.

Question 13

What is a hyphen used for?

Accepted Answer

A hyphen joins words or parts of words so that they work as one: mother-in-law, merry-go-round, twenty-one, a long-tailed monkey, ex-captain. It is short and has no spaces round it. In handwriting it also splits a long word at the end of a line. If the words read correctly and clearly apart, leave the hyphen out.

Question 14

Is it T-shirt or T shirt?

Accepted Answer

T-shirt. Some everyday words always wear a hyphen: T-shirt, U-turn, great-grandmother, mother-in-law. Others differ by dictionary: X-ray and x-ray are both listed. When you are unsure, look the word up in one dictionary and follow it every time. Without its hyphen, great grandmother reads like a grandmother who is simply great.

Question 15

Is it sugar-free or sugar free?

Accepted Answer

Before a noun, sugar-free: a sugar-free sweet. Two describing words that make one picture before a noun are joined: a long-tailed monkey, a red-hot pan, a blue-eyed cat. Many of these, like sugar-free, are listed in dictionaries with the hyphen, so they keep it after the verb as well: This sweet is sugar-free.

Does this line join words, or break the sentence?