How to use a/an before an abbreviation? Hello, I have a question related to the use of the indefinite articles "a" and "an" before a noun. I know that the rule goes as: if the initial sound is that of a vowel, then we use "an" before the word; but if the initial sound is that of a consonant, then we use "a" before the word. My question concerns the application of such a principle for abbreviations! For example, imagine we are talking about movies. Then, we would write "a Romance Movie". Now, suppose we want to abbreviate Romance Movie as "RM". The question is: should we write (i) "a RM"? since RM is a shortcut for Romance Movie, and we write "a Romance Movie"; or (ii) "an RM"? since we actually read it as [are'eme] (i.e., the sound of "r" followed by that of "m")? -- Thank you Luiz da Silva