Does “i before e except after c” work?
Research
Across 767 English words in common written use that contain ie or ei, the rule holds 456 times and fails 158 times (74.3% right); 156 more pairs are not counted, their i and e being in different syllables or parts of the word (method below). After c, cie occurs in 25 words and cei in 23: more words break the rule after c than keep it, but in running text cei is written about 1.9 times as often (receive, ceiling).
The count
| Position | Letters | Rule | Words | Common examples |
|---|---|---|---|---|
| after c | ei | follows the rule | 23 | received, receive, receiving, ceiling, perceived, receiver, receipt, perceive |
| after c | ie | breaks it | 25 | species, efficiency, sufficient, conscience, sufficiently, efficiently, insufficient, deficiency |
| not after c | ei | breaks it | 133 | their, either, foreign, eight, weight, height, protein, neighborhood |
| not after c | ie | follows the rule | 433 | believe, friend, series, field, view, tried, movie, review |
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract); lowercase words in common written use (Zipf 2.5 or more, about 3 in 10 million words, in wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media)), without misspellings and obsolete or nonstandard forms. Each occurrence of ie or ei is counted once.
The ie/ei mistakes people search
| Wrong | Right | Searches a month |
|---|---|---|
| reciept | receipt | 14,940 |
| recieved | received | 7,950 |
| recieve | receive | 4,300 |
| seige | siege | 2,180 |
| sheild | shield | 2,010 |
| cheif | chief | 1,960 |
| recieving | receiving | 1,670 |
| acheive | achieve | 1,440 |
| wierd | weird | 1,410 |
| theif | thief | 980 |
| peice | piece | 980 |
| shiek | sheik | 950 |
| fiesty | feisty | 930 |
| hygeine | hygiene | 930 |
| caffiene | caffeine | 880 |
| beleive | believe | 830 |
| reciever | receiver | 780 |
| yeild | yield | 570 |
| heirarchy | hierarchy | 570 |
| athiest | atheist | 560 |
| albiet | albeit | 530 |
| breif | brief | 470 |
| freind | friend | 460 |
| percieve | perceive | 430 |
| foriegn | foreign | 360 |
Source: Bing searches in the United States, the average month from September 2025 to August 2026 (Microsoft Advertising keyword data through DataForSEO, read September 30, 2026).
Method and limits
The rule is tested on spelling alone, the way it is taught (“i before e except after c”). Its longer versions (“or when sounded like a, as in neighbor and weigh”) excuse some of the failures; the count here does not apply them, because a reader checking a spelling does not know the sound rule's exceptions either. An i and an e that are not one vowel are not counted: those in different syllables of Wiktionary's split (sci·ence, ex·pe·ri·ence) and those in different parts of the word (be·ing, the·ist, de·ity). Where Wiktionary records no split, the American transcription decides: a vowel sound followed straight by another is two syllables (so·ci·e·ty, /səˈsaɪ.ə.ti/); a word with neither takes the verdict of the longest word inside it that has one (bio·science). A word with both a one-vowel and a two-syllable pair (friendlier) is left out whole, so the counts slightly understate the rule's cases.
How this was written
The text of this analysis was written with AI tools; its figures are queries on PlainSpell's database, and the text was checked against them. No figure is typed by hand. Editorial policy · Report an error.