to not know whether to use 'which' or 'that' in a sentence

[MariaWaria]

For example,

"I was one of the people THAT won the competition"
OR
"I was one of the people WHICH won the competition."

Can someone explain how to use which and that?

People who.

I was one of the people who won the competition, no? Am I going to have to rethink everything I say?

it's who

Or is it WHO?

Yes it's who.

I think it should be WHOM won but tbh would not say that myself , more likely to say THAT won

I was one of those people who

Yes, it's who in your example

But I do know what you mean. There are plenty of times when people use which when I would say that - and vice versa - and it makes me doubt whether I'm right.

Definitely who in this context. This article is good. <a class="break-all" href="https://www.google.com/amp/s/amp.theguardian.com/media/mind-your-language/2011/oct/17/mind-your-language-that-which#ampshare=www.theguardian.com/media/mind-your-language/2011/oct/17/mind-your-language-that-which" rel="nofollow" target="_blank">www.google.com/amp/s/amp.theguardian.com/media/mind-your-language/2011/oct/17/mind-your-language-that-which#ampshare=www.theguardian.com/media/mind-your-language/2011/oct/17/mind-your-language-that-which

Yes, it's WHO

Whom is wrong here too, it should only be used as the object of a preposition or verb. Who relates to the subject.

That and which are decided by whether a comma is required.

OK, here is the difference:

I found a job that makes me happy.

I found a job, which makes me happy.

In the first example, the job itself makes me happy. There's the implication that I was unhappy at the previous job.

In the second, finding a job - any job - was what made me happy. Previous, I was unhappy because I was unemployed.

"Which" should generally be preceded by a comma. Say the sentence aloud with a pause to see what emphasis you want.

For who and whom, switch out he or him. The bell tolls for whom? The bell tolls for him.

Who is at the door? He is at the door.

'which' is incidental, you could drop that bit of the sentence and it wouldn't alter the key message. Which also always has a comma.

Bill Bryson did a good little book called Troublesome Words, it's helped me no end.

For who and whom, switch out he or him. The bell tolls for whom? The bell tolls for him.

Who is at the door? He is at the door

Simply brilliant.
.