Generally, as a rule, the indefinite article ‘a’ is used before words that begin with a consonant sound; and its counterpart ‘an’ is used before words that begin with a vowel sound. This is simple, but not that simple, I must say.
Note here that I’m writing about words that begin with either consonant sounds or vowel sounds, not the letters of the English alphabet. Let’s consider some examples:
ana university /juːnɪˈvəːsɪti/: /j/ is a consonant sound hence the use of article ‘a’aan umbrella, an apple, an orange, an apostle, an onion etca ruler, a game, a computer, a union, a DVD player etc
an SMS /es.em.es/, an MP3 /empiːˈθriː/, an INEC official etc. Here, one has to pay attention to the phoneme that begins the word or say the acronym.
In English pronunciation, there are words with silent ‘h’; I mean words where the letter ‘h’ is not pronounced. And as you’ve learnt in the previous examples, the sound that begins a word or any word is our consideration here and this sound determines whether the indefinite article ‘a’ or ‘an’ will precede the word.
For example, we say an hour /ˈaʊə/ because the ‘h’ in hour is silent. Therefore, words beginning with silent ‘h’ have an indefinite article ‘an’ that precedes them. In the same vein, words having the ‘h’ pronounced will have an indefinite article ‘a’ preceding them.
Other examples are:
an honest man not
a honest manan heir not
a heira hotel not
an hotela hero not
an heroa house not
an houseIt’s an honour
a honoura history
an historyprofessora habit
an habit
It is important you master those words beginning with silent ‘h’ and use them correctly when you speak with people.
With love and everything English,
Francis
Great job, Sir.