Japanese phrase
誰だかわかりませんでした。 dare da ka wa ka ri ma se n de shi ta
Meaning
I couldn't tell who it was.
When to use it
Says the speaker could not identify someone. The polite past form suits a report about an unfamiliar person seen or heard earlier.
Example dialogue
さっきの人、誰でしたか？ sa kki no hito dare de shi ta ka
Who was that person earlier?
すみません、誰だかわかりませんでした。 su mi ma se n dare da ka wa ka ri ma se n de shi ta
Sorry, I couldn't tell who it was.