Usually when a word starts with a vowel, we will use "an" before it. But for union, it is "a union" not "an union." It is not explained in the previously mentioned a vs an why union is an exception. It explains how to know exceptions for h like hotels.

Also are there any exceptions for the opposite side, where there should be an "a" but is an "an" instead? (Unfortunately I have no example of a case like this.)

  • 2
    "An institution of higher learning"... Remember, it's not words that begin with a vowel, it's a vowel sound. "union" begins with a "yoo" sound, which is a consonant sound, like Ukulele.
    – Catija
    Aug 11, 2015 at 20:38
  • But they did not explain the exception and I still don't understand the exceptions. :( Aug 11, 2015 at 20:39
  • Perhaps if you rephrase your question to be specific to the "union" question and not to the broader "a vs an" situation.
    – Catija
    Aug 11, 2015 at 20:40
  • 4
    @user1470901 It's not an exception. The pronunciation governs whether a or an is used, not the spelling, as three people have now explained. Thus, a one-piece suit, an FBI badge, a xylophone, an X-ray, a euro account — and it's an herb garden for Americans even if it's a herb garden for most Britons.
    – choster
    Aug 11, 2015 at 20:49
  • 2
    All other words, such as "cake", "pie", and "user" (which begins with a y sound), are preceded by "a". — the above is written in the linked question. "Union" is exactly parallel to "user." It is not an exception.
    – herisson
    Aug 12, 2015 at 2:54

1 Answer 1


The a/an-rule is based on pronunciation, not on spelling. Though the word union is spelt beginning with a vowel, the u is pronounced "you":


So, this is why it is accompanied by a rather than an and this is also the case for many other words starting with a vowel, have a look at these:

  • a user
  • a European


  • an ultimatum
  • an orange

Note that there are words which start with an h and when that h is not pronounced, these words also go with an:

an honor

However, if this h is pronounced, then the article used is a:

  • a hill
  • a heathen

Here's a short but clear article that explains the usage of a/an: Articles: A versus An

  • @DogLover Please don’t answer duplicates. No one will ever find them. And they should be closed anyway.
    – tchrist
    Aug 11, 2015 at 22:05
  • @tchrist I did not answer this question; I commented on an answer.
    – Dog Lover
    Aug 11, 2015 at 22:11

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