Add -miş/-mış/-muş/-müş plus a person ending to mark a past event you did not see yourself: hearsay, something you worked out from evidence, or a surprise. Plain -di is reserved for what you personally witnessed.
Examples
- Toplantı iptal edilmiş.
- Apparently the meeting was cancelled.
- Duyduğuma göre yeni bir işe girmiş.
- From what I hear, he has started a new job.
- Çok yorulmuşsun.
- You look like you got really tired.
The mistake to avoid
Using -miş for your own witnessed actions makes you sound as if you doubt your own memory.
Where this fits in
İfade ve nüans, Turkish C1: Master register, idiomatic expression, and conveying fine emotional nuance.