Is it possible to make a superscript or subscript in Kate?

For some characters like numbers sure, you can use something like KCharSelect, the special characters plugin for KRunner, or Character Selector plasmoid for that. In Linux you can also hit ^ once and then a number to make it superscript. E.g. ¹²³⁴⁵⁶⁷⁸⁹⁰.

The question is why you would want to do that.

As Hans said, only through unicode characters. Kate is a plain text editor and does by design not support any kind of text formatting.

Hans wrote:For some characters like numbers sure, you can use something like KCharSelect, the special characters plugin for KRunner, or Character Selector plasmoid for that.

Thanks, I used that, but now I have switched to LibreOffice.

Hans wrote:In Linux you can also hit ^ once and then a number to make it superscript. E.g. ¹²³⁴⁵⁶⁷⁸⁹⁰.

Where in Linux? It does not seem to work in Kate.

Hans wrote:The question is why you would want to do that.

I was making notes for my studies, but I have switched to LibreOffice Writer now. I miss Kate, because of vi mode.

Take your notes in LaTeX -- then you get the best from both worlds.