crack somebody up - 把某人逗笑
Ryan is such a funny guy. He always cracks me up.
laugh my butt off - 笑得屁滚尿流
B: Baijie, what're you watching that's so funny?
A: It's Zac Efron and Taylor Swift doing the dance dare! I'm laughing my butt off.
是Zac Efron和Taylor Swift在别人背后偷偷跳舞！矮哟笑死我了！
I died laughing - 我差点笑死。
I saw this T-shirt at Disneyland that had a picture of Donald Duck quacking and it said "The original Angry Bird". I died laughing!