In English orthography, compound words can be written in a variety of ways - as a single word, e.g. bedroom, with a hyphen (make-up) or with a space (washing machine). But what features actually determine the choice between these alternatives? "There is no official body that formulates orthographical rules for the English-speaking world," as Christina Sanchez-Stockhammer, Professor of Modern English Linguistics at LMU, points out. As a result, even the dictionaries cannot agree on the spelling of English compounds. "That may sound chaotic. But there are a few rules of thumb that can provide some guidance." To tease these rules out, Sanchez-Stockhammer took a closer look at the spelling of over 10,000 English compounds. Based on this data, she developed a spelling algorithm and a free online tool that suggests the most probable spelling of English compounds.
"In English, there are compound words belonging to all parts of speech. In most cases, one particular spelling intuitively suggests itself, but even native speakers sometimes find it difficult to decide between the possible alternatives. My aim was to identify the underlying reasons for the variation," Sanchez-Stockhammer explains. She analysed whether variables such as the compounds' structure, length or stress pattern were in any way correlated with their spelling. In the course of the project, which was carried out in collaboration with a programmer and a statistician, she was ultimately able to reduce the complexity of English compound spelling to its essentials: "A whole range of factors can have an influence on how compound words are typically spelled. But on a general level, it all boils down to a few simple guidelines."
Sanchez-Stockhammer found that the most significant variable is part of speech. Compound adjectives (like world-famous) or verbs (like to blow-dry) are usually written with a hyphen. Compound nouns such as washing machine, on the other hand, are usually spelled with a space - provided that they contain more than three syllables. Nouns with two syllables, by contrast (e.g. bedroom), are written in the closed-up form, unless the second component consists of only two letters - in which case the hyphen once again comes into play (e.g. make-up). This explains why hotdog is not hyphenated.
"By using these rules, one will arrive at the most frequent spelling in about 75% of all cases," says Sanchez-Stockhammer, who enjoys using the online tool herself - as do increasing numbers of native and non-native speakers of English. "Of course, there are exceptions to these rules of thumb, and there are also additional rules that have an impact on the orthography of English compounds," she points out. - These further complexities are spelled out in her new book on English Compounds and their Spelling, which has just been published by Cambridge University Press.
Prof. Dr. Christina Sanchez-Stockhammer
Deputy chair of Modern English Linguistics
Department of English and American Studies
Phone: +49 (0)89 2180-3085
Sanchez-Stockhammer, Christina: English Compounds and their Spelling, Cambridge, 2018. (=Studies in English Language)