If it’s been a while since you last enrolled in an English course, you might be rusty on some usage points. Here’s a quick refresher about some common mistakes.
- Many writers wonder when to write everyday as one word, and when to write it as two. Here are some points to remember:
Every day (two words) is an adverb:
Joe packs his own lunch every day to save money. CORRECT
(Think: Joe packs his own lunch each day to save money.)
Everyday (one word) is an adjective:
I’m packing just my everyday clothing for the trip.
(Think: I’m packing just my ordinary clothing for the trip.)
You can easily learn the difference between everyday and every day even if you’re unfamiliar with grammatical terminology. Memorize this box (or copy it and carry it with you):
Need more help? Here’s a trick that has helped many writers: “ordinary” (everyday) is one word; “each day” (every day) is two.
2. There’s a controversy about what to do with used to when it’s combined with didn’t. Many authorities say that both used to and use to are correct:
I didn’t used to like Chinese food. CORRECT
I didn’t use to like Chinese food. CORRECT
Some people, however, have a strong preference for didn’t use to. I’m one of them, and I’m happy to report that the prestigious Cambridge Dictionary agrees with me. Click here to read more.
3. When you use either…or in a sentence, skip the first part and go straight to or. That part of the sentence will determine your verb. (You can download a free subject-verb agreement handout at this link:
Either the aides or the supervisor has the key to the storage room. CORRECT
Compare this version, which switches the words around:
Either the supervisor or the aides have the key to the storage room. CORRECT
4. It’s easy to make mistakes with subject-verb agreement. Try this sentence: Is have the correct verb – or should it be has?
Overuse of prescription painkillers have/has become a huge problem.
There are two ways to think about this sentence, and both will get you to the correct answer. “Of prescription painkillers” is a prepositional phrase, so you should skip over it when you think about the subject and verb:
Overuse of prescription painkillers has become a huge problem.
Overuse of prescription painkillers has become a huge problem. CORRECT
Here’s another way to do it: The beginning of the sentence is the most important part, so you should focus on the word overuse. (Click here to learn more about the beginnings of sentences. And click here to download a free handout about subject-verb agreement.)
Overuse of prescription painkillers has become a huge problem. CORRECT

