From my understanding, @Ekopalypse is not an English speaker,

Yes, correct.

yet his posts make perfect sense.

I’m not sure about that. :-)

I understand he uses deepl.com for translating from his language to > English before posting.

Most of the time I do.
If I can give short answers, I sometimes try to do it without a translator.
And I think it is easy to find out which posts are written with and without deepl.com. :-)

Need to stop by Menu >> Language

If by that you were trying to repeat me when I said “just make your choice from the Language menu”, then I’m not sure why you did that because I had covered it ~7 hours earlier.

I did not say to go into Settings and periodically change the settings for opening a New document.

That’s strange, because you pointed the OP to that section of the Preferences.

These are all the difficulties of translating into English

From my understanding, @Ekopalypse is not an English speaker, yet his posts make perfect sense. I understand he uses deepl.com for translating from his language to English before posting.

I myself made an additional context menu for changing the syntax of the document.

Ah, well that’s a valuable contribution to this thread that could perhaps help the OP. Nice one.

I would have pointed out the Default Language setting in my answer, except the OP mentioned he uses TWO languages in “new” files. Since there is only ONE available as the default (obviously), it may be best to leave that setting as Normal Text.

Yup, just make your choice from the Language menu.