Use Of The A And An Questions Medium
You should use "an" before words starting with a vowel cluster when the sound of the cluster is a vowel sound. The choice between "a" and "an" is determined by the sound, not the actual letter. For example, you would say "an hour" because the "h" in "hour" is silent and the word starts with a vowel sound. Similarly, you would say "an honest person" because the "h" in "honest" is also silent. However, if the vowel cluster is pronounced with a consonant sound, you would use "a" instead. For example, you would say "a university" because the "u" in "university" is pronounced as a "y" sound, which is a consonant sound.