An or in?
an is an article meaning “Used before a vowel sound”; in is a preposition meaning “Contained by; inside”. Use an as an article and in as a preposition. In written English (wordfreq, 2021 data) in is about 5.5 times as common as an.
What is the difference between an and in?
| an | in | |
|---|---|---|
| Part of speech | article, number, conjunction, noun, preposition, prefix, suffix | preposition, verb, adverb, noun, adjective, prefix, suffix |
| Meaning | Used before a vowel sound Used before /h/ in a stressed or unstressed syllable The first letter of the Georgian alphabet, ა (Mkhedruli), Ⴀ (Asomtavruli) or ⴀ (Nuskhuri) | Contained by; inside Within the bounds or limits of At or towards the interior of a defined space, such as a building or room |
| Example | I'll be there in half an hour | The dog is in the kennel |
| Forms | ans, on-, a-, ANs | ins, inning, inned, in., i-, il- |
| Pronunciation | /ˈæn/ [ˈæn] [ˈan] | /ən/ /ɪn/ /ɘn/ |
| In writing | 3,388 times per million words | 18,621 times per million words |
Sources: an and in in the English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0); written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
Every current meaning of an and in
an
- 1
Used before a vowel sound
I'll be there in half an hour
- 2
The first letter of the Georgian alphabet, ა (Mkhedruli), Ⴀ (Asomtavruli) or ⴀ (Nuskhuri)
- 3
In each; to or for each; per
I was only going twenty miles an hour
- 4
Alternative form of on-
ancome, aneal, anent
- 5
not; used to make words that have a sense opposite to the word (or stem) to which the prefix is attached. Used with stems that begin with vowels and "h"
- 6
Alternative form of ana-
- 7
Alternative form of ad- (“to, toward”)
- 8
Of or pertaining to; an adjectival suffix appended to various words, often nouns, to make an adjective form. (Often added to words of Latin origin, but also used with words of other origins. When a…
Rome + -an → Roman
in
- 1
Contained by; inside
The dog is in the kennel
- 2
At or towards the interior of a defined space, such as a building or room
Suddenly a strange man walked in
- 3
A position of power or influence, or a way to get it
His parents got him an in with the company
- 4
Located indoors, especially at home or at one's office or place of work
Is Mr. Smith in?
- 5
Abbreviation of inch or inches
- 6
Abbreviation of integrase
- 7
in, into, towards, within
inhold, inmove, intake, inthrill
- 8
in, into
il- before l, e.g. illusion im- before b, m, or p, e.g. imperil ir- before r, e.g. irrigate
Source: the English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0); obsolete, archaic, dialect and rare senses left out.
Which is more common, an or in?
an appears 3,388 times per million words; in 18,621 times per million words.
an 3,388 times per million wordsin 18,621 times per million words
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).