Which article to use before acronyms? "a" or "an"?

Generally articles are not used with acronyms (initials that can be pronounced as a word), whereas they are used with initialisms (initials where the letters themselves are pronounced). For example: 'NASA' (acronym) doesn't get an article, but 'FBI', 'ESA', and 'DDR' (initialisms) do. The general rule for indefinite articles is to use 'a' before words beginning with consonant sound and 'an' before words beginning with vowel sounds. The trick here is to use your ears (how the acronym is pronounced), not your eyes (how it's spelled). HIV (pronounced "aitch eye vee") begins with a vowel sound (ai), so 'an HIV' patient is correct. Another example: you would say 'an MBA'. (em-bee-ay, as it begins with the 'e' sound even though it is spelled with an M). If the word following the indefinite article begins with a vowel sound, use an; if it begins with a consonant sound, use 'a'.

When the indefinite article is used before an acronym, the choice of form (a or an) depends on pronunciation, not on spelling; in other words, use a if the acronym begins with a consonant sound, and an if it begins with a vowel sound: a NATO decision (a before the consonant sound n)

an

There is no need of articles before 'Acronyms'.

an will use. because the last word of the first letter is a. vowel

an

an

A