Isn't the translation "Wczoraj ona mi powiedziała." also correct? I do realise that it makes an emphasis on SHE ("Yesterday SHE [as opposed to somebody else] told me. - but still...
Added "Wczoraj ona mi powiedziała" and "Ona mi wczoraj powiedziała" (the third one worked already).
It is correct, however "Ona mi wczoraj powiedziała" or even "Ona mi powiedziała wczoraj" sounds more natural to me.
Why mi and not mnie?
Theoretically "mnie" could be correct, but it would create such a strong emphasis on ME!, that I don't think it makes sense in this sentence.
She told me.....what?
This sentence definitely needs some context :D
You're right. I've changed the sentence to "She told me yesterday".