reagovati

1. to react; to respond
   Kako je reagovao kad je čuo vest? — How did he react when he heard the news?
   Policija je brzo reagovala. — The police responded quickly.
2. (of the body, a substance) to react; to respond
   Organizam dobro reaguje na terapiju. — The body is responding well to the treatment.
   Ova kiselina reaguje sa metalom. — This acid reacts with metal.

What one reacts to is introduced with na + accusative: reagovati na kritiku.