Student or Learner
Which one is correct?
I had spoken with Sally on yesterday concerning John.
I had spoken to Sally on yesterday concerning John.
You can use either, but your sentence is not clear. Did you speak to her yesterday or did you speak to her about yesterday? "on yesterday" is not correct.
In normal usage, we would probably start with "Yesterday" -
Yesterday I spoke to Sally about John.
Yesterday I had spoken to Sally about John. Today I was going to speak with John about Sally.