Hyphenation is intended for the proper splitting of words in natural language texts. When a word occurring at the end of a line is too long to fit on that line within the accepted margins, a part of it is moved to the next line. The word is thus wrapped, i.e., split and partially transferred to the next line.
The wrapping can be done only at specific positions within words, which generally, though not always, are syllable boundaries. For example, in Spanish one can split re-ci-bo, re-u-nir-se, dia-blo, ca-rre-te-ra, mu-cha-chas, but not in the following positions: *recib-o, *di-ablo, *car-retera, *muc-hac-has.
In this way, hyphenation improves the outer appearance of computer-produced texts through adjusting their right margins. It saves paper and at the same time preserves impression of smooth reading, just as without any hyphenation.
The majority of the well-known text editors are supplied now with hyphenation tools. For example, Microsoft Word has the menu item Hyphenation.[2]
Usually, the linguistic information taken for such programs is rather limited. It should be known which letters are vowels (a, e, i, o, u in Spanish) or consonants (b, c, d, f, g, etc.), and what letter combinations are inseparable (such as consonants pairs ll, rr, ch or diphthongs io, ue, ai in Spanish).
However, the best quality of hyphenation could require more detailed information about each word. The hyphenation can depend on the so-called morphemic structure of the word, for example: sub-ur-ba-no, but su-bir, or even on the origin of the word, for example: Pe-llicer, but Shil-ler. Only a dictionary-based program can take into account all such considerations. For English, just dictionary-based programs really give perfect results, while for Spanish rather simple programs are usually sufficient, if to neglect potentially error-prone foreign words like Shiller.