Which phrase is correct?

1. The article "a" is rendered "an" when a vowel sound follows. 2. The rule depends on sound, not spelling. 3. In "hour" the "h" is silent, so the word begins with a vowel sound. 4. In "hotel" the "h" is pronounced, so "a hotel" is correct. 5. "Umbrella" begins with a vowel sound, so it needs "an". 6. So the correct phrase is "an hour". **Why the other options fail:** - A hour is wrong because hour begins with a vowel sound. - An hotel is wrong because hotel begins with a pronounced h. - A umbrella is wrong because umbrella begins with a vowel sound. _Source: Wikipedia, "Article (grammar)", section "introduction" (revision 1378409904)_