As if I don't grind my teeth to powder enough over people who think "it's" is a possessive (no, the cat ate it's dinner is not correct), or who throw in apostrophes where they don't belong (no, they're selling apple's is not correct), there's a new stranger in town: jealous.
"Hey, you have a nice car! I'm jealous!"
"You went on a nice vacation! I'm jealous!"
No, you are not. You are envious.
If someone has something that you would like to have, or goes somewhere that you would like to go, you feel envy, not jealousy.
You are jealous when you have something, and you're afraid that someone might take it away. He's afraid that guy's going to steal his date; he's a jealous boyfriend.
If you looked over at him, and saw him with that gorgeous woman and wished you were in his shoes, you'd be envious of him. She sees you and winks. He's jealous. It takes two to create envy (one to have something, the other to envy it), while it takes three to be jealous.
Yes, there is a difference. Now just don't get me started on alot, ahold, and alright.