"Is it Zack-wa or Zack-ga?"

Zack comes from Japan. If you are asked to translate this into Japanese, what will be your answer?

You would have 2 options:

「ザックは日本からきました。」or 「ざっくが日本からきました」

Native Japanese speakers decide which answer is appropriate, dependings on the question being answered.

When you were asked “Where does Zack come from?”, your answer will be:

「ザックは日本からきました。」The emphasis is put on the BACK after the particle.

You already know we are talking about Zack. The core information is “from Japan”

When asked, “Who comes from Japan?” your answer will be:

「ザックが日本からきました。」The emphasis is put on the FRONT before the particle.

The core information being asked is “WHO”, so “Zack” is spotlighted.

Japanese looks quite troublesome, but as long as you focus on key points, you'll be just fine. I look forward to seeing you in my lesson!

Zack