Use a hyphen to tie words together in a group. You won't need to do this often. :) Marie-Hélène's 4th point explains why. Without a hyphen, you may not be sure if the "little used car" is a car that is little-used (rarely used), or a used car that is little. If a hyphenated word is commonly used for long enough, and is therefore widely recognised, the two words can be fused together. We can fuse them because we are very familiar with the expression. In older writings, you'll see "pot-hole" or "tea-pot" instead of the modern "pothole" and "teapot". This is where you see the evolution process of the language. ;) Some of the hyphenated examples above I've already seen 'fused': nonexistent, nonviolent, antifascist, neonazi, undersecretary. Some words won't fuse well, so we keep the hyphen: vice-president (not "vicepresident"... yet...), and the fraction examples. Keep numbers tied together, but still as separate words. They don't make sense as a single word. If you're not sure, read or search for the expression first before using hyphens. And never fuse words together unless you've already seen it done several times before.

Hi... There have been a number of questions concerning when to use hypens. The following is an excerpt from The Economist magazine's style guide. © The Economist Newspaper Limited 2004 Use hyphens for: 1. FRACTIONS (whether nouns or adjectives): two-thirds, four-fifths, one-sixth, etc. 2. MOST WORDS THAT BEGIN with anti, non and neo. Thus anti-aircraft, anti-fascist, anti-submarine (but antibiotic, anticlimax, antidote, antiseptic, antitrust); non-combatant, non-existent, non-payment, non-violent (but nonaligned, nonconformist, nonplussed, nonstop); neo-conservative, neo-liberal (but neoclassicism, neolithic, neologism). Words beginning Euro should also be hyphenated, except Europhile, Europhobe and Eurosceptic; euro zone and euro area. Some words that become unmanageably long with the addition of a prefix. Thus under-secretary and inter-governmental. Antidisestablishmentarianism would, however, lose its point if it were hyphenated. A sum followed by the word worth also needs a hyphen. Thus $25m-worth of goods. 3. SOME TITLES vice-president, director-general, under-secretary, secretary-general, attorney-general, lieutenant-colonel, major-general, field-marshal but general secretary, deputy secretary, deputy director, district attorney 4. TO AVOID AMBIGUITIES a little-used car a little used-car cross complaint cross-complaint high-school girl high schoolgirl fine-tooth comb (most people do not comb their teeth) third-world war third world war