How it works
Each sheet draws 8 of our sentences. A blank stands where writers slip, with the right word and the mistake under it: its or it's, then or than, fewer or less, could have or could of, lie or lay.
Read the full guide
Word mix-ups
This set holds words that sound alike or nearly so: its and it's, then and than, to, too and two, lose and loose, accept and except, affect and effect, whose and who's. In our sentences affect is always the verb and effect the noun.
Usage slips
The second set under Set is grammar, not spelling: could have and never could of, fewer for things you count and less for what you measure, I or me after and, a verb that agrees with its subject, one negative and not two, lie or lay.
- For Leo and me, drop Leo and: the director chose me, so the director chose Leo and me.
- There, their, they're, your and you're are left out here; each has a page of its own.
Questions and answers
Can I get the common grammar mistakes worksheet as a PDF?
Yes, from the print window: press Print worksheet and choose Save as PDF as the printer. We host no PDF file: the sheet is drawn in your browser, and the Set and Questions menus change what it holds.
What are the most common grammar mistakes?
No list is official. These sheets cover its and it's, then and than, affect and effect, could of, fewer and less, me and I, and lie and lay, among others.
Is it could of or could have?
Could have. Could of is a spelling of how could've sounds, and it counts as a mistake in writing. The same goes for should have, would have, must have and might have.
When do I use fewer and when less?
Fewer goes with things counted one by one: fewer chairs, fewer mistakes. Less goes with what is measured as a whole: less water, less traffic. Our sentences avoid money, time and distance, where less is also used with numbers.
Is there an answer key?
Yes. It prints as the last page with the right word circled and written into each blank. Uncheck Add an answer key as the last page under More options to leave it off.