Swiss German is not context-free (unlike virtually all other languages) (1985) [pdf]

Another funny thing about Swiss German is that we don't have a simple past. There is no "We ate" or "I made" or "You played". Rather, we always say stuff like "We have eaten" or "I have made" or "You have played". I.e., we only ever use present perfect. It's rather weird and as a native, never noticed this particularity until it just came to me once when I casually switched from speaking Swiss German to High / "normal" German (or English, for that matter).

I had a look through this and I didn't get the main idea. I understood that it you take a grammatical sentence in Swiss German and swap the accusative and dative cases around for one or more nouns, you get an ungrammatical sentence. I don't speak a language with cased nouns so maybe I'm missing something, but I didn't find this surprising. Wouldn't this be true also in German for example?

Then this feature of Swiss German seems to be related to the 'context-freeness' of the language. I couldn't understand what this property was from the article, or from the (very technical) Wikipedia page [1]. Can someone give a less technical explanation of context-freeness?

[1] https://en.m.wikipedia.org/wiki/Context-free_grammar

Swiss German is the only language I know to have diminutive verbs.

"Mer gönd go pöschtele."

It's quite the quirky language.

Are there other language with diminutive verbs?