At first glance, pluralizing words in English might look trivially easy. All you need to do is add -s: one word, two words. There are plenty of irregular plural forms too, though, like one child, two children and one mouse, two mice. This Language Matters instalment asks why the final -s is the dominant way to mark plural nouns, but not the only one.

In the modern world, astrology is often treated as a hobby, hovering somewhere between self-help and light entertainment. As the English language shows, though, the possibility that heavenly bodies might shape earthly life was a deadly serious concern for our ancestors.

Neologisms (new words, senses or expressions) are added to living languages all the time, through coinages, borrowings or revivals, and many do not stay relevant for long. Faced with the near-infinite potential of lexical creativity, lexicographers (the people tasked with creating dictionaries) can include only a selection of new words.