Formation: you're = you are

Usage: You're the most beautiful girl I've ever seen.

Meaning: You are the most beautiful girl I've ever seen.

Formation: you'll = you will

Usage: You'll be warm if you put on your coat.

Meaning: You will be warm if you put on your coat.

Formation: you've = you have

Usage: You've probably noticed the new table in the kitchen.

Meaning: You have probably noticed the new table in the kitchen.

Formation: you'd = you had

Usage: You'd better study if you want good grades.

Meaning: You had better study if you want good grades.

Formation: you'd = you would

Usage: You'd have bought that dress if it was a different color.

Meaning: You would have bought that dress if it was a different color.

Formation: you'd have = you would have

Usage: You'd have eaten dessert if you had more money.

Meaning: You would have eaten dessert if you had more money.

Formation: you would've = you would have

Usage: You would've eaten dessert if you had more money.

Meaning: You would have eaten dessert if you had more money.