Some mistakes come from writing what we hear. In fast speech, could have sounds like “could of,” and supposed to sounds like “suppose to.” Formal writing uses the actual words. Like tricky pairs, these are about knowing what the words are.
| What you may hear | What formal writing uses |
|---|---|
| could of, should of, would of | could have (could’ve), should have, would have |
| suppose to, use to | supposed to, used to |
| alot | a lot (two words) |
| alright | all right (many editors still expect two words) |
| irregardless | regardless |
| for all intensive purposes | for all intents and purposes |
Key idea
Write could have, should have and would have (or their contractions), supposed to and used to, a lot, all right and regardless in formal writing.
Why it works
In speech, the sounds blur and no one minds. On the page, “could of” looks like a different grammar (could + of) and readers notice. Many people say these forms in conversation; formal written English uses the full forms.
Worked example: Could of
“I should of studied for the quiz.”
- The helping verb after should is have.
- “Should’ve” is the contraction, which sounds like “should of.”
Answer: I should have studied for the quiz. (or should’ve)
Worked example: Used to
“We use to live in Ohio.”
- The meaning is a past habit.
- The past form is used to; the -d is hard to hear before to.
Answer: We used to live in Ohio.
Common mistake
Writing what you hear: could of, alot, suppose to. Alright is common in informal writing and appears in dictionaries, but many teachers and editors still mark it in formal work, so all right is the safe choice. Irregardless is heard in speech; formal writing uses regardless.