Learn Dutch: De tweede ronde begint pas, maar ik ken de categorie al. - The second round is only just beginning, but I already know the category.

We use kennen when we are talking about being familiar with a noun, such as a person, place, or thing. Because the speaker knows "the category" (de categorie), which is a noun, kennen is the right choice. You would use weten (to know) if you were talking about knowing a fact, or before a subclause (like "I know that it is starting").

I know pas can mean a bank card or a passport. What does it mean in this sentence?

Here, pas is an adverb meaning "only just" or "barely". It emphasizes that the second round is at its very beginning. It creates a nice contrast with al (already) in the second half of the sentence: it is only just beginning, but I already know the category.

Why is the word order in the second clause ik ken de categorie? Doesn't the conjunction change it?

The word maar (but) is a coordinating conjunction. Coordinating conjunctions (like en, maar, of, and want) connect two main clauses but they do not affect the word order at all. That is why the second half keeps the standard subject-verb order: ik ken.

Why is al placed at the very end of the sentence instead of next to the verb?