How to say "I see" or "got it" in Chinese

It's 我 (I) + 知道 (know) + 了 (particle indicating a change of state). The 了 shows that you've just come to know something, so it means "now I know" or "I've got it."

Use this in casual and semi-formal settings to show you've understood what was just said. It's not a direct translation of "I know" (which would be 我知道 without 了); the 了 makes it about the moment of understanding. Avoid using it to mean "I already knew that" — that would sound dismissive.