你先忙

I’ll leave you to sth

e.g. Well, I’ll leave you to your work.
你先忙你的工作吧。

let you get back to sth

e.g. I’ll let you get back to your housework.
你先忙你的家务吧。

你先请

after you

A: Can I pour you some coffee?
我给你倒点咖啡吧？
B: Oh no, after you.
噢，不用，你先来吧。

我支持你

I will support you. = You have my support.
I’m with you.
I’m behind you.
I’m on / by your side.
I will always be here / there for you.
I will back you up.
I have / got your back.
e.g. Whatever decision you’re going to make. I’m behind you.
无论你怎样决定，我都支持你。

你天生就是这块料

be a natural at sth
You are a natural at this. 你天生就是这块料。
e.g. She won’t have any troubles learning to ride a horse, you can see she’s a natural.
她学习骑马不会有任何困难，可以看出她天生就是这块料。