Here are the completions for the sentences provided:

**13. We’ve never seen such a funny film.**
It’s the funniest film we’ve ever seen.

**14. He is the most interesting person I’ve ever met.**
I have never met anyone as interesting as he is.

**15. I’ve never heard such a beautiful song.**
It’s the most beautiful song I’ve ever heard.

**16. I have never worn such a warm sweater.**
It’s the warmest sweater I’ve ever worn.

**17. We have never read such an interesting book.**
It’s the most interesting book we’ve ever read.