I'm learning English now. I've heard some American sayings like "I'm screwed. you're screwed. or it sucks" that I don't quit catch. would you please tell me what these sayings mean? many thanks in advance.
I'm screwed = I'm in trouble, and there's no way to get out of it. (This problem could be of my own making.)

He screwed me = He did something that caused problems for me.

That sucks = I don't like this at all!

While "screwed" is showing up more often, "sucks" is still considered a very mild "naughty phrase" and could cause offense.
all sexual metaphors for " I have been done down by someone" in the case of "screwed", and "It doesn't meet with my approval" in the case of "sucks - unwise to use in anything except the most informal circumstances.
thank you very much for your reply.
You need to watch "South Park". It's plenty of "screw you", "it sucks" etc. I recommend this "cartoon"