Study: What Makes English Words Hard to Pronounce (413 Words Analysed)

We analysed 413 commonly mispronounced English words across 30 categories and classified each one by the linguistic reason it causes trouble. The result: most pronunciation difficulty is not random. It clusters into a handful of predictable causes — and the largest single cause is not silent letters, as often assumed, but words borrowed from other languages.

Method

Our corpus is the curated word set behind PronounceIt's commonly-mispronounced word lists: 413 entries in 30 hand-built categories, each with a verified plain-English respelling. Every entry was included because it is a genuinely well-known trap, not to pad a round number.

For this analysis we assigned each category to one primary cause and summed the words in it (363 words classified). We deliberately excluded the flagship “50 Most Commonly Mispronounced English Words” list (50 words) from the breakdown, because it is a cross-section of the other categories and would double-count.

What this is and isn't: this is a structured analysis of a curated corpus, not a survey of speakers. It shows why the words that trip people up are hard; it does not claim to measure how often individuals mispronounce them. We report no percentages we cannot derive from the data itself.

Finding 1 — Difficulty clusters into six causes

Finding 2 — Borrowed words are the biggest cause

The largest bucket is borrowed from another language (137 words across 10 categories). Brand names, food and drink, wine, fashion houses, car marques, place names and people's names all fail for the same underlying reason: the word obeys another language's spelling rules. Gnocchi is Italian, so gn is “ny”. Quinoa is Quechua. Hermès is French. No amount of English phonics helps — you have to be told, or hear it.

Practical consequence: for borrowed words, memorising rules is useless. Looking them up is the only reliable strategy.

Finding 3 — Silent letters are over-blamed

Silent letters get the most attention in pronunciation teaching, but they account for only 50 words (14% of classified entries) in our corpus. They are also the most learnable cause, because they follow patterns: learn “MB at the end = silent B” once and you get climb, lamb, thumb, comb, bomb for free. See our complete silent-letter pattern guide.

Finding 4 — Some words are hard with no wrong sound at all

31 words in the corpus involve no unfamiliar sound whatsoever — only misplaced stress or a failure to reduce unstressed vowels. RE-cord (noun) versus re-CORD (verb) uses identical phonemes; only the emphasis differs. This is why stress errors are disproportionately damaging: listeners lose the word even though every sound was “correct”. See word stress rules and the schwa.

Finding 5 — Not every “mistake” is a mistake

43 words sit in genuinely contested territory: usage is split, has shifted over time, or differs between British and American English. Often is accepted both with and without the t. Niche is both “neesh” and “nitch”. Insisting on one form here is prescriptivism, not accuracy — which is why PronounceIt plays four accents rather than declaring a single winner.

Where the words come from

The eight largest categories in the corpus:

What this means if you're learning

1. Borrowed word? Don't reason — look it up and listen.
2. Silent letter? Learn the pattern, get dozens of words at once.
3. Sounds fine but people misunderstand you? It's almost certainly stress.
4. Two versions online? Both may be right; pick one accent and stay consistent.

You can hear every one of the 413 words in this corpus in four accents, with IPA and syllable breakdowns, on the commonly-mispronounced lists — or look up any word at all with the pronunciation tool.

Reuse and citation

These figures are derived from PronounceIt's curated corpus and are recomputed automatically whenever it changes. You are welcome to cite or quote this analysis with a link to this page. Corrections and additions are genuinely welcome — get in touch.