How to form a sentence like this correctly?

Question

1. You should tell us the things that you think they are negative.

2. You should tell us the things that you think are negative.

I came up with this example sentence and I would like to form sentences like that but I'm not sure which one is correct and why. Would you tell me, please? What I mean is "When you see anything negative, you should tell us".

Answer 1

The they is not required because 'that' in your sentence talks about them!

In other words, here, the things are indicated by that and thus, you don't need to re-introduce those things in your sentence by putting 'they'.

Here you go:

You should tell us the things that you think are negative.