Learn Dutch: De agent identificeert de overvaller. - The officer identifies the robber.

Usually, no. While it can mean "agent" in specific contexts (like a geheim agent for "secret agent"), in everyday Dutch, an agent is simply a police officer (short for politieagent). For a sports or real estate agent, you would use a different word, like makelaar.

If someone asked "Is hij de overvaller?", how would we reply using this lesson's grammar point?

You would reply Ja, hij is het (Yes, he is). Even though de overvaller is a de-word and a person, Dutch uses the neutral pronoun het when replacing a noun phrase that acts as a predicate (a noun that follows a linking verb to describe what someone is).

What exactly is the difference between an overvaller and a dief?

An overvaller commits an overval (a hold-up, mugging, or raid). This implies a direct confrontation, often with violence or threats (like an armed robber). A dief (thief) is a broader term that usually implies stealing secretly without confrontation, like a pickpocket or burglar.

What is the infinitive of identificeert and how is the 'c' pronounced?