Intensifiers (čak, čak i, baš)

čak — even

You have had the card čak since A2; here is its grammar. It marks something as MORE than expected, usually with i before a noun: Čak i djeca razumiju ovo pravilo. Before a comparative it means even bigger, even better: Danas je čak toplije nego jučer.

baš — really, exactly

baš pins emphasis on the word after it: Baš sam sretan zbog tebe! It can point at an exact thing (baš ovaj, baš danas — precisely this one, today of all days): Zašto baš ja?

The polite no

In answers, baš i ne softens a refusal: — Sviđa ti se film? — Baš i ne. (Not really.) Compare Baš me briga (I couldn't care less) — same particle, sharper tone.