Only 129 of 32,455 English words break the a/an rule

English: A vs. An

Only 129 of 32,455 English words break the a/an rule

Red Blob Games explores the a vs. an rule, which depends on spoken vowel sounds, not written letters. After analyzing 32,455 words, the author found just 129 exceptions. The post includes visualizations of the first two letters and reflects on spending a day parsing cmudict and re-learning d3.js, noting that LLMs could have sped up the one-off code.

I was surprised that only 129 of the 32,455 words in my list needed exceptions.
  1. hbn

    A funny quirk of English I never noticed until I started learning Spanish:

    In Spanish, to say for example, "he is a doctor," you would say "él es médico." Which more literally translates to "he is doctor," which feels unintuitive coming from English. Spanish DOES have an equivalent for "a" - "un/una", so the natural thing for an English speaker to say would be "él es UN médico", but I understand that to be awkward/unnatural.

    But then I realized, when you say the same sentence in plural - "they are doctors" - you don't have an article. You don't say "they are some doctors" (I had to Google, apparently "some" isn't an article anyway?)

    So Spanish ends up more consistent - Singular: "Él es médico." Plural: "Ellos son medicos."

    Unlike English - Singular: "He is a doctor." Plural: "They are doctors."

  2. bugufu8f83

    > if word.startswith("ub"): return False

    An uber-rich man riding in an Uber installed an Ubuntu package.

    I'm actually a bit surprised by this rule. Is this line there entirely due to the word "ubiquitous"? I think it is.

  3. abraxas

    What gets me as a non-native speaker far more than "a vs an" is the "a vs the" conundrum. I still don't quite get when something needs to be "indefinite" and I've been speaking English for close to forty years. My native tongue lacks articles altogether and it's soo bloody hard I feel hopeless I'll ever master them fully.

  4. shagie

    It's avoiding two distinct vowel sounds in succession.

    Consider other variations of this rule.

    In French, one would say "l'hôpital" rather than "le hôpital" because the 'h' is an aspirated breath (try saying "a aspirated" rather than "an aspirated") leading to an initial vowel sound.

    In Irish, the word for father is "athair". To say "her father" it becomes "a hathair" https://en.wikipedia.org/wiki/Prothesis_(linguistics)

    In Turkish, it can be seen with araba (car). "I saw the car" -> "Arabayı gördüm." (note the 'y' to avoid two vowels). Book is kitap and "I saw the book" is "Kitabı gördüm." Which doesn't need the additional consonant sound between the final sound and the "ı".

    Whatever language you speak, it likely has some form of this rule.

    And other languages have the quirk too (like the "a unicorn" or "a university"). For example, in French there's l’hôtel and l'hôpital. But if you've got the hedge... it's la haie... or even more egregiously, the marmoset is le ouistiti.

  5. theanonymousone

    The most problematic for me as a non-native has been "the" vs "nothing", i.e. when one can/should put the definite article.

    Pre-LLM I was joking that real AI is whatever can make that decision correctly 100% of times.

  6. smusamashah

    The A becomes An for the same reason as the linking R https://en.wikipedia.org/wiki/Linking_and_intrusive_R

    As a non-native now living in UK I noticed this R sound in some accents. Someone said 'Java (r)Options' which when I asked they didn't even realise they were adding it. Both this R and N in an seem to be used break the continuity of vowels between words.

  7. Dwedit

    There's also "the" vs "the". As in "the boy ate the apple". First 'the' ends with a schwa sound. Second 'the' ends with 'ee' sound.

  8. nikolay

    English is so much easier than, let's say, Greek, Russian, or French (at least these I know firsthand). Even Bulgarian, my native language, which is simpler than Russian, is much harder than English, with a lot more things to memorize. Two things in English take time: punctuation and vocabulary (with all the nuances of words). Everything else is easy-peasy!

  9. throwawayk7h

    I'm always curious why sometimes I pronounce the as /ðə/ ("thuh") and sometimes as /ði/ ("thee"). I don't really know what governs this but I expect it's the presence of a vowel at the start of the following word. However, only some vowels. Does anyone have an answer?

  10. eviks

    Interesting analysis

    > [LLM It doesn’t need to be clean or maintainable. It only needs to be correct

    But correctness is precisely the issue with LLMs?

    But also

    > I would’ve spent more time on the trie simplification algorithm and less time on parsing cmudict and re-learning d3.js.]

    You could've spent nothing on D3 because the result is bad/poorly readable - much worse than a simple table alphabetically-aligned interception table, which I could use to answer curious questions such as "how can I compare "A" and "O" in terms of exceptions? or "which letter has the most exceptions"?")

    (and the blue color is out of place, vowel/consonant split should visually be the same "category", not black/colord. Red for exceptions is fine)

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2026-09-19