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a
/ə/
indefinite article
I saw a cat in the garden.
The word 'a' introduces a non-specific singular noun ('cat') in this sentence.
formal
used before singular nouns when mentioning someone or something for the first time in a context or when the person listening does not know which particular one you mean
She has a dog and a cat.
The article 'a' is used before 'dog' and 'cat' to indicate one of many possible pets.
A teacher should be patient.
Here, 'a' generalizes the role of a teacher, not a specific one.
Used before consonant sounds (including 'y' and 'w' sounds). For vowel sounds, use 'an'.
formal
used before nouns to refer to a single thing or person that is not identified or specified
A Mr. Smith called for you.
'A' indicates an unspecified person named Mr. Smith.
Common in formal or indirect references.
formal
used before a number to indicate something that happens regularly
I go to the gym three times a week.
'A' indicates frequency in this context.
Often used with time expressions like 'day', 'week', 'month', or 'year'.
Pro Tip
Sound-Based Usage
Always choose 'a' or 'an' based on the sound that follows, not the letter. For example, 'a unicorn' (y sound) uses 'a', while 'an umbrella' (u sound) uses 'an'.
Gold Rule
Article Rules
1. 'A' is for singular, non-specific nouns. 2. 'The' is for specific or previously mentioned nouns. 3. Omit articles before plural or uncountable nouns when generalizing (e.g., 'Dogs are loyal' vs. 'The dogs are loyal').
Word Origin
From Old English 'ān' (one), related to German 'ein' and Dutch 'een'. The form 'a' emerged in Middle English due to vowel reduction.
Usage Notes
1. Use 'a' before consonant sounds (e.g., 'a book', 'a university' where 'u' sounds like 'y'). 2. Use 'an' before vowel sounds (e.g., 'an apple', 'an hour'). 3. In some dialects, 'a' may be pronounced as /eɪ/ before vowels (e.g., 'a apple' → /eɪ ˈæpəl/), but standard usage requires 'an'.
English Dictionary