I'm the one who...

We use this expression to specify that I am the person who is special in some way.

我们用这个表达来强调，我们在某方面的独特作用，区别于他人。

A: If we take this bag to the police, perhaps they'll give us a reward.

如果我们把这个包交给警察，兴许他们还会奖励我们。

B: I'm the one who should have a reward, because I'm the one who found the bag.

我才是那个该得到奖励的人，因为我是哪个找到这个包的人。