Use “an” instead of ‘a’ if the following word starts with a vowel sound, e.g. ‘an article’, ‘an hour’. (EN_A_VS_AN) Suggestions: `an` URL: https://languagetool.org/insights/post/indefinite-articles/ Rule: https://community.languagetool.org/rule/show/EN_A_VS_AN?lang=en-US Category: MISC