A macron is a diacritic. It is the small horizontal bar written over a vowel to indicate its 'length'. Its use in normal English writing is reserved for certain technical matters, such as marking scansion (nowadays mostly for quantitative metres, but sometimes used in the past to indicate stressed syllables). As it is used in the teaching of Latin, it can be seen in
- ā (the sound of the vowel in 'car' and 'are', IPA: /ɑː/);
- ē (the sound in 'where' and 'air', IPA: /e/);
- ī (the sound of '-ee-', as in 'sleep' and 'peace' (IPA: /iː/);
- ō - a sound not part of the English language, as normally spoken, but found in many other European languages, such as Swedish (IPA: /o/);
- ū, as in 'goose' and 'shoot' (IPA: /uː/).
Observant students may have noticed that the IPA symbols replace the macron mark with a lengthening mark, the ː above.