Irregularities of any kind prove difficult for people—especially linguistic irregularities. They’re taxing on the long-term memory. For example, there are so many words ending in –cede (accede, intercede, precede, recede, secede) that the one exceptional spelling, supersede, is often misspelled to conform to the etymologically unrelated –cede words. It happens all the time. In print sources, the correct spelling occurs in comparison to the misspelling at a ratio of 12 to 1.
In law, think of all the words ending in –um (bonum, maximum, minimum, quantum, etc.). Then there’s that one common phrase that is exceptional: in personam. In print sources, the correct spelling occurs in comparison to the misspelling (as if it ended –um) at a ratio of 786 to 1. But sad to say, the misspelling has appeared in law reviews and judicial opinions.
One more example: de minimis. So many Latinisms end in –us that the ending –is is comparatively infrequent among Latin loanwords. Hence many writers, perhaps deficient in Latin, misspell de minimis as if it ended in –us. In print sources, the correct spelling occurs in comparison to the misspelling at a ratio of 19 to 1.
Below are some of the more common irregularities in English spelling that throw off less-than-vigilant writers:
There’s no handy rule to help you know which ending is correct, so you must simply remember the words and phrases that present problems, and prompt yourself to double-check if you’re uncertain. Don’t rely on a spell-checker, which may well substitute a grossly wrong word for a simple misspelling.