Hello,
I know this has been discussed before, but I have a question about two specific sentences. Here they are:
- I am looking for someone who/that can help me learn French.
- I don't like people who/that throw in the towel at the first of difficulty.
I'd go with "who", but I seem to be the only one.

Apparently, there's something wrong with "who", but I don't know what.
Thank you.