Calling someone Sir or Madam also exists in English and is nothing special.

You left out most of the interesting things.

For example the vocative case is partially dissapearing. Someone from Finland can actually understand this topic, since Finnish has multiple cases - more than in Polish language (meanwhile English has one case and if we try very hard we can squeeze something similar to a case - so let's say it has two).

> English has one case and if we try very hard we can squeeze something similar to a case - so let's say it has two

This isn't a correct way to describe English grammar. You can either say it has no cases or four cases with no inflections (because it definitely has subjects, objects, indirect objects, and possessives).

Presumably your native language doesn't inflect in the nominative or something like that and your English teacher once gave you your statement as a convenience fact, but the vast majority of native English speakers have never heard of grammatical case (ones who have, have typically studied inflected foreign languages). In Linguistics, it might be used to describe English and other uninflected languages (it depends).

> You left out most of the interesting things. For example the vocative case is partially dissapearing.

The grammar is changing in many ways (for example, the inanimate masculine is being replaced with the animated, kroić kotleta), but this was about honorifics.

In English you can use 'sir' as an insult, which is quite creative.