I think that usually 'A' is used before a noun beginning with a consonant and 'an' before one beginning with a vowel. <br/><br/>BUT, what is the rule for words beginning with an 'h' <br/>Which is correct 'an horse' / 'a horse' or 'an hoax' / 'a hoax'. <br/><br/>Are these exceptions ?Are there any other exceptions? <br/><br/>thanks