so so - not so bad
马马虎虎 Mǎmǎhǔhǔ
Literally “stupid birds fly first”, this expression talks about the fact that less-skilled people need to put more effort in to succeed.
笨鸟先飞 Bèn niǎo xiān fēi
literally means “people mountain people sea”.
人山人海 Rén shān rén hǎi
the subway station is totally packed with people!
地铁里人山人海 Dìtiě lǐ rén shān rén hǎi
Nice to meet you
幸会幸会 Xìng huì xìng huì
means that something is a total mess. You can use it to describe tangible things like messy rooms, or more abstract things, like a messed up life.
乱七八糟 Luàn qī bā zāo