“I have done this yesterday.” You’ve probably said it. Here’s why it feels right and why it isn’t.

In German, “Ich habe das gestern gemacht” is correct. You use haben + past participle even when you mention a specific time.

English works differently. The moment you say “yesterday”, “last week” or “on Monday”, English switches to simple past: “I did this yesterday”.

“Have done” tells English speakers the time is open and unspecified. Add “yesterday” and the sentence breaks.

This catches almost every German speaker at some point. It’s a language trap, not a careless mistake.

Quick win: Specific time? Simple past. “I did this yesterday.” “She called last week.” “We finished on Monday.“