How is the usage of 信任 and 相信 different ？ According to my understanding the scope of 信任 is more than the scope of 相信 . For example if we are talking about a person or a few people , we might say 我相信你 but for countries we might use it as 美国信任韩国. Is that correct or are there other usages ?
Here they emphasize that 信任 only applies to other people (or organizations etc. created by people), believing that person's character is good, whereas 相信 (unlike 信任) can apply to people's speech, and other matters that you trust are true.
Their example sentences:
- 公司领导很 [相信 / 信任] 他，最近让他当了一个部门的经理。
- 既然用他就应该 [相信 / 信任] 他，用人不疑嘛。
- 我不 [相信] 他说的话。
- 你这么努力，我 [相信] 你一定能学好汉语。
- 我 [相信] 这件事是真的。
They also highlight how the object of 信任 cannot be the subject (unlike 相信). More specifically they write:
相信's object can be oneself, 信任's object cannot be oneself. [my translation]
giving the example
我 [相信] 自己的判断是正确的。
I'm not a native Chinese speaker but I've always used 相信 to mean believe (related to truth/falsity) and 信任 to mean trust/confidence (related to success/failure).
我相信你 I believe you. I believe what you just said. I think you are telling the truth. I don't think you are lying.
我信任你 I trust you. I trust in your ability. I have faith in you. You won't let me or yourself down. I am confident that you will succeed. I am confident that you will not fail.
While 信任 can only be used for a person (or a group of people), 相信 can be used for both a person or a non-person object. I will here discuss what's the difference when used for a person.
信任 focuses on describing the characteristic of the person. When you say "我信任小张", that means 小张 has your endorsement to be a trustworthy/capable person.
When you say 我相信小张, it means you believe in 小张. It focuses on your action of believing instead of on the personality/ability of 小张.
You may tend to use 信任 over 相信 if your relationship with 小张 is close. However, even with this said, the two sentences above are describing almost the same situation.