A few months ago, I wrote this post about the top ten incorrect phrases I come across in the books I edit. Today, we’re going to talk about a related issue: what happens when writers use real words in the wrong way.

Below are five couplings of words that have distinct applications and meanings but that many authors use interchangeably. Don’t just leave it up to your copy editor to fix these mistakes for you; study up on them so that you’re clear on what to use when. 

1) effect and affect

This pair of words is challenging because they’re pronounced similarly, have multiple meanings, and can each be either a verb or a noun. However, for practical purposes, effect is most often a noun, whereas affect is most often a verb. You have a positive effect on someone, but you affect that person in a positive way, or you see the effects of sun damage on your skin, but the sun affects everyone’s complexion differently.

2) coincidentally and ironically

If I had a dollar for every time I’ve heard someone use ironically when she means coincidentally . . . well, I wouldn’t be writing this post in the first place, because I’d already be retired. As Merriam-Webster defines it, irony is either “the use of words that mean the opposite of what you really think” or an “incongruity between the actual result of a sequence of events and the normal or expected result.” A coincidence is simply “a situation in which events happen at the same time in a way that is not planned or expected.” So, for example, if you were just talking to your friend Bill about your other friend Bob and then you run into Bob at the grocery store that same day, that’s merely a coincidence. However, if you were just telling Bill that you don’t think Bob even knows what a grocery store is and then you run into Bob at your local Safeway, that’s ironic.

3) imply and infer

When you imply something, you suggest it, e.g., “Yes, I’m implying that you’re not a good driver.” When you infer something, you deduce it based on someone’s implication, e.g., “I’m inferring from your comments that you don’t think much of my driving.” 

4) comprised and composed

The phrase comprised of, which peppers everything from corporate writing to literary fiction, is incorrect. Comprise is a verb that takes no preposition, whereas of follows composed. Correct usage is either “This dish comprises five main ingredients” or “This dish is composed of five main ingredients.” If you can’t keep these two terms straight, just go with the latter option across the board.

5) farther and further

Farther refers to physical distance, whereas further means “to a greater extent” or “in addition to.” So the restaurant is farther away than you expected, but an unresolved scientific phenomenon requires further exploration—as does the subject of today’s discussion.

Have a grammar question? Leave it in the comments below.