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Every word, spelled
& explained.
Definitions, IPA pronunciation, etymology, confusable pairs and homophones across English, Spanish, Portuguese, French and German, drawn from the open Wiktionary corpus.
Fast multi-language word intel: definitions, etymologies, confusables, homophones & misspellings across EN/ES/PT/FR/DE – 6M+ words from Wiktionary.
- 6.9M
- words
- 3.4M
- confusable pairs
- 5
- languages
The short version
Across five languages, the words writers double-check most are long, affix-heavy spellings and short look-alike pairs a single keystroke apart, PlainSpell maps every one from the open Wiktionary corpus.
- 6.9M
- words, 5 languages
- 3.4M
- confusable pairs mapped
- their vs there
- most-confused English pair
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026). Definitions, IPA pronunciation, etymology, confusable pairs and homophones. Free, no sign-up.
Choose Your Language
Most Confused English Words
View all →The Hardest English Words to Spell
Full ranking →Hardest English words to spell
Ranked by how many distinct misspellings appear across the corpus
- internationalization
internationalization
30 recorded misspellings
- counterintelligence
counterintelligence
28 recorded misspellings
- disproportionately
disproportionately
28 recorded misspellings
- characteristically
characteristically
27 recorded misspellings
- indistinguishable
indistinguishable
27 recorded misspellings
- interdisciplinary
interdisciplinary
27 recorded misspellings
- intergovernmental
intergovernmental
27 recorded misspellings
- misinterpretation
misinterpretation
27 recorded misspellings
What this shows Long, affix-heavy words like ‘internationalization’ attract the most spelling variants, the more morphemes a word stacks, the more places a writer can slip.
The Alphabet, by the Numbers
Full analysis →Which letters begin the most English words
The 26 letters of the alphabet, shaded by how many headwords start with each
What this shows‘S’, ‘P’ and ‘C’ open more English words than any other letters, a footprint of the Latin and Greek prefix clusters (sub-, super-, pro-, con-) that English borrowed wholesale; ‘X’, ‘Y’ and ‘Z’ trail far behind.
Spelling & Language Guides
What Is PlainSpell?
PlainSpell is a free multi-language word reference built on Wiktionary data via kaikki.org. Every word entry includes its definition, IPA pronunciation, part of speech, etymology, and usage examples, where available.
Our confusable pairs feature helps you understand the difference between commonly mixed-up words like affect vs effect, complete with side-by-side comparisons and memory tricks.
Homophone groups show you which words sound identical but differ in spelling and meaning, essential for non-native speakers and language learners.
Misspelling corrections let you find the right word even when you're not sure how to spell it. Type a misspelling and PlainSpell finds the correct form instantly.
Data sourced from Wiktionary contributors under CC BY-SA 3.0. PlainSpell is an independent reference publisher, not affiliated with Wiktionary or the Wikimedia Foundation. How each field is sourced, derived, and corrected is documented in our methodology and editorial & corrections policy.
Frequently Asked Questions
What is PlainSpell?
PlainSpell is a multi-language word reference tool covering English, Spanish, Portuguese, French, and German. It helps you find word meanings, check spelling, and discover commonly confused word pairs.
Where does PlainSpell get its word data?
Word data is sourced from Wiktionary, a collaboratively edited multilingual dictionary, licensed under Creative Commons BY-SA. The database includes 6.9 million words and 3.4 million confusable word pairs.
Is PlainSpell free?
Yes, PlainSpell is completely free. You can look up words, find definitions, and explore confusable pairs across 5 languages without any account or subscription.
What are confusable word pairs?
Confusable pairs are words that are commonly mixed up due to similar spelling or pronunciation, like "affect" vs. "effect" or "complement" vs. "compliment." PlainSpell identifies 3.4 million such pairs across all supported languages.
Explore the Corpus
Dive deeper into the PlainSpell word data:
Related Guides
Editorial context for the plainspell dataset, methodology, comparisons, and deep dives into the underlying records.
Research
Original analysis from our editorial team, every statistic derived from our own database. See all research.
The Most Confusable English Word Pairs
The pairs most likely to be confused are short, high-frequency function words separated by a single character. We rank them and explain why frequency times small edit distance is the recipe for confusion.
ResearchLongest English Words by Misspelling-Variant Count
Long, affix-heavy words generate the most distinct misspelling variants. We rank the worst offenders from the corpus and trace the morphology behind them.
ResearchWhich Letters Begin the Most English Words and Confusables
S, P, and C lead the English word count; S, C, and B lead the confusable pairs. We trace the pattern back to Latin and Greek prefix clustering.
Style Guide Spelling Decisions
Per-word rulings on disputed English spellings, what AP Stylebook, Chicago Manual, MLA, APA, Garner's, and Merriam-Webster actually prescribe, with citations to the published editions. Browse all style-guide rulings.
email vs e-mail
How AP, Chicago, MLA, APA, and Merriam-Webster all settled on the unhyphenated form.
Style Guidehealth care vs healthcare
AP keeps the noun open and hyphenates the adjective; industry usage favors the closed form.
Style Guideeveryday vs every day
The single most common style-guide distinction: adjective is one word, adverbial phrase is two.
Where to start
Three ways into the corpus, depending on what you came for.
- Verifying one word? Search it, or browse a language A–Z for definition, IPA, etymology and misspellings. English A–Z
- Mixing up a pair? The confusable comparisons settle which spelling means what, side by side. Confusable pairs
- Want the patterns? The rankings and guides explain why certain words are hardest to spell. Most misspelled