Compound words combine two or more terms to make a new word. They can be tricky, though, especially when working out whether to write a word as a closed compound (i.e. with no space between the terms, such as in \u2018bedroom\u2019). In this post, we look at some common errors.\n\nWhat Are Compound Words?\nCompound words are made up of two or more other words. They can be written as open compounds, hyphenated compounds, or closed compounds:\n\n\n \tOpen compounds are written as separate words, but they are conventionally used together (e.g. full moon, mobile phone, ice cream).\n \tHyphenated compounds occur when two or more terms are joined with a hyphen (e.g. mother-in-law, well-known, T-shirt).\n \tClosed compounds are written as a single term but combine two or more words that could be written separately (e.g. notebook, boyfriend, childlike).\n\nAll of these are importantly distinct from contractions, where two words are combined by dropping letters from one or both terms.\nOne key difference here is that contractions are considered informal, while compound words are accepted in formal writing.\n\nWhen to Hyphenate a Compound Word\nThe rules about hyphenating compound words are fairly flexible, but they can still be useful. The most common guidelines are to hyphenate:\n\n\n \tWhen using a compound modifier before the word it modifies (e.g. a well-laid plan or a mind-numbingly boring speech).\n \tWhen writing compound numbers between twenty-one and ninety-nine.\n \tWith ages and time spans in years (e.g. a seven-year itch).\n\nIt\u2019s also worth noting that compound adjectives are not hyphenated when one term is \u2018very\u2019 or an adverb ending in \u2018-ly\u2019:\nShe found a perfectly formed gemstone. \u2713\nShe found a perfectly-formed gemstone. \u2717\nNor are they hyphenated when they come after the noun they modify:\nThe plan was well meaning. \u2713\nThe plan\u00a0was well-meaning. \u2717\nAs mentioned, there is some variation here (e.g. 'old-fashioned' is almost always hyphenated, even when it appears after the term it modifies). But the rules above can help if you're unsure whether to hyphenate a word.\n\nOne Word or Two?\nPart of the confusion surrounding closed compound words is that they often have specific meanings that differ from their constituent parts. \u2018Everyday\u2019, for example, is an adjective meaning \u2018ordinary\u2019 or \u2018routine\u2019. It should be used in a sentence like this:\nMy everyday clothes were in the wash, so I wore pyjamas to the pub.\nThis isn\u2019t quite the same as \u2018every day\u2019, which is written as two words and means \u2018each day\u2019. It\u2019s important not to get these terms confused if you want to be clear about what you mean:\nI go to the pub every day. \u2713\nI go to the pub everyday. \u2717\nSimilar issues arise with terms like \u2018already\u2019 and \u2018altogether\u2019, which have distinct meanings from \u2018all ready\u2019 and \u2018all together\u2019. This makes it vital to check how you\u2019re using compound words.\nWith \u2018alright\u2019 and \u2018all right\u2019, meanwhile, we have a different problem. Technically, both mean \u2018satisfactory\u2019 or \u2018safe\u2019, but \u2018alright\u2019 is widely considered a little informal. It may gain acceptance one day, but for now it\u2019s best not to use it in formal writing.\n\nNouns and Verbs\nAnother major cause of errors with compound words is whether they\u2019re being used as nouns or verb phrases. Typically, the noun forms are written as a single closed compound:\nMy computer setup cost me thousands of dollars.\nHere, for example, \u2018setup\u2019 is one word because it refers to a thing, not an action. The verb form of this term would be the two-word \u2018set up\u2019:\nIt took me hours to set up my computer.\nOther terms where these rules apply include \u2018workout\u2019 (verb = \u2018work out\u2019), \u2018backup\u2019 (verb = \u2018back up\u2019) and \u2018handout\u2019 (verb = \u2018hand out\u2019). Look out for these and similar terms in your writing.\n\nIncorrect Compounds\nFinally, some terms are incorrectly written as compound words even when there is no correct version. Examples include \u2018alot\u2019 (which should always be \u2018a lot\u2019) and \u2018nevermind\u2019 (which should be \u2018never mind\u2019 unless you\u2019re referring to the Nirvana album).\n\n\n[caption id="attachment_3241" align="aligncenter" width="365"] For us, Kurt Cobain's musical legacy is outweighed by the number of spelling errors he's inspired.[\/caption]\nThese are simply errors and should be avoided in your written work. Most spellcheckers will highlight these as incorrect, but make sure to check a dictionary if you\u2019re unsure.\nAnd if you'd like any extra help with compound words in your writing, our proofreaders can help. Submit a free trial document today to find out more.