@futurebird caveat: Not a teacher!

I'm not sure what level your students are at, what specifically you are teaching them or how much control you have over the course but...

If you've not seen it already you might like to look at https://hedy.org . It's a language designed for teaching that gradually adds syntax as you explore concepts until you reach a subset of syntactically valid Python. The error messages are also very useful, thoughtfully designed and tested in classroom settings.

Excellent talk by the creator here www.youtube.com/watch?v=6ED36HvQSvk

Honorable mention to Elm and Rust for having excellent error messages too!