Learn German: Gibt es etwa objektive Kriterien für dieses Stadium? - Are there even objective criteria for this stage?

Words ending in the Latin suffix -um are highly predictable: they are almost always neuter. This is why the singular forms are das Kriterium and das Stadium.

How do we form the plural of these -um loanwords?

Instead of adding standard German plural endings, they follow a Latin-derived pattern. You drop the -um and add -en. Thus, das Kriterium becomes the plural die Kriterien, and das Stadium becomes die Stadien.

I learned etwa as meaning 'about' or 'approximately'. Why is it translated as 'even' here?

Here, etwa is used as a modal particle rather than an adverb of approximation. In questions, it expresses doubt, surprise, or disbelief, similar to saying 'even' or 'by any chance' in English. The speaker is expressing skepticism that such criteria actually exist.

Why does the adjective objektive end in -e here?

The phrase objektive Kriterien is the direct object of the phrase gibt es, which always requires the accusative case. Since there is no article before the adjective, it takes the strong plural ending -e.