In the chaos of spelling of the English language, some rules provide comfort — until you realize that the number of exceptions renders a rule nearly useless as a memory aid. Such is the case with the rule that in vowel pairs, i comes before e except when the pairing follows c.
The pairing ie is the default setting: Believe, die, and friend are just a few of the many words that follow the rule. However, exceptions are numerous, as exemplified in the sentence “Seize their eight feisty neighbors being weird.” And although the order after c is often ei (ceiling, deceit, receive), the order is often inverted (science, species, sufficient). To be more useful, the rule should continue, “or when pronounced like a long a, as in weigh or like a long e.”
The rule that i comes before e except after c is contradicted by the fact that more than twenty times as many words have the letter sequence cie as the sequence cei, so that’s not a very useful rule.
Also, the sequence ei often does not follow c. This is true in many categories of words, including the following ten groups:
- proper names, such as Keith
- chemical names like caffeine
- words in which ei is pronounced like a long e, such as leisure (many exceptions, such as piece)
- words in which ei is pronounced like a schwa (a weak “uh”), such as forfeit
- words in which ei is pronounced like a long a, such as weigh (this sound is never spelled ie, except in the American English pronunciation of lingerie)
- words in which ei is pronounced like a long i, such as height (exceptions include die)
- rare cases of ei pronounced, for example, like a short a, such as heifer
- words in which the vowel-and-consonant sound rhyming with ear is pronounced, such as weird (exceptions include pierce)
- words in which the vowel-and-consonant sound rhyming with heir is pronounced, such as their (this sound is never spelled ier)
- words in which e and i are each part of a separate syllable (albeit, being, reignite)
Ultimately, it may be wise to forget that such a rule exists and always check spelling of words that may have an ie or an ei combination.