I don't think IQ tests language skills specifically. ChatGPT can't even do basic mathematics. It is too one sided
Linus Ekenstam had ChatGPT take an IQ test (except the visual part). Result: 89
I don't know if this speaks to the uselessness of IQ tests or that most people are dumber than AI, I'm guessing the former.
https://linusekenstam.substack.com/p/i-had-chatgpt-take-an-iq-test-so
Discussion
Open the article and check the results for arithmetic.