A hyphen is a punctuation mark in the form of a dash. It is used to join two or more words to form compound words, most common of which are compound nouns.
Hyphen forming compound words
Hyphen are often used in fractions and compound numbers from twenty-one to ninety-nine.
Hyphens are used to separate prefixes from words
Hyphen is used for a word break at the end of a line
The newspaper reported that the town was hit by a torna-
do last evening.
Hyphens used to avoid confusion
- The new owner has decided to re-form the club.
(Without the hyphen, the word reform has got a different meaning.)
- They are going to re-mark the papers due to the record high number of passes.
(Without the hyphen, the word remark has got a different meaning.)
A dash is double the length of a hyphen.
A dash is sometimes used instead of a colon or a semi-colon.
- "Quick! Go now – the police are coming for you!"
Do we have all the things – the rods, plastic worms, extra hooks, net, knife, first-aid kit, and what else?
When dashes are used in a sentence, commas are not used to separate interrupting phrases.
- No: She looked at the dresses, -- a few of them, -- deciding on the one she should buy.
- Yes: She looked at the dresses -- a few of them -- deciding on the one she should buy.
A dash used to show a sudden deviation or emphasis.