English is rich in homonyms: words that are spelled the same or sound the same but have different meanings. Words that are spelled the same but have different meanings, like row and row are called homographs, while those that sound the same (blue and blew, for example) are homophones.
These types of pairings are traps for unwary learners and native speakers alike, and President Trump fell into one on Monday when he confused council and counsel in a tweet about the former acting US Attorney General Sally Yates (the tweet was later deleted and a new version published with the correct word in place).
Both counsel and council have a range of meanings and derivatives (such as counsellor and councilwoman) but while counsel is both a verb and a noun, council is only ever a noun. A useful phrase that the tweeting President shows no signs of observing any time soon is to keep your own counsel, meaning to keep your opinions to yourself.
You can find out more about homonyms by searching for the terms homonym or homophone on the Macmillan Dictionary blog.
