I know that apostrophes should only be used to show possession or in contractions, yet when I am typing I often throw in extra needless apostrophes out of habit.
In the same way, most students know the difference between you're and your, they just get overwhelmed when writing and make the mistake without thinking.
So, how to get students to use your and you're properly?
First make sure they know the difference. The Internet is fantastic here. There are grammar comics, songs, and websites that point out the difference as well as many memes. Find some funny examples and come up with some on your own if need be. Check out the Venn diagram on the right for a basic guide on the differences and similarities between you're and your.
Check that they understand by giving them some sentences and having them explain what it means. You can use YouTube clips to make this a bit more fun, or just say them yourself. For example.
“'You're the one that I want' did I mean you are or your?”
What does: Your "you're" you're using may be wrong mean?
The “you're” that belongs to you that you are using may be wrong
It can also help to compare it to similar word pairs in English. He's vs His (which sounds similar), or She's vs Her, I'm vs. My and finally It's vs Its (which has its own set of problems).
Remember: “Good grammar is the difference between thinking 'You're tops' and 'Your tops'.”
Next, discourage contractions. When speaking we use contractions naturally, and that's fine since you don't have to worry about pronouncing your differently than you're. Informal writing also tends to have contractions; however try to encourage students to write out words in full whenever possible. This tends to be the fastest way to get rid of this mistake as they won't likely use “you are” when they mean to say “your” and vice versa.
If that doesn't work, or your students are disinclined to write out entire words make sure they double check their work out loud. I try to avoid grading written work around people as I end up reading their essays out loud. That's because I can hear mistakes more clearly than I can read them. If your students read their work out loud and read contractions in full (so they would see can't but read cannot) they will likely find all their mistakes. If their brains keep auto-correcting their mistakes, have them read backwards, starting with the last sentence .
This opens itself up to SO many games! It can be done with flyswatter. Just put Your and You're on the board. It works even better if you rotate which word is where and you only have two groups. Say a sentence, “Your shirt is ugly” and then have the students race to hit the correct word. In this case hitting the wrong word would result in the other team getting the point.
This also works very well with dictoglosses since students would have to figure out if your or you're made more grammatical sense.
What activity would you do to review? What tips do you have when teaching the differences?