Start a question with "So..." when you want to check whether you understand something. You say "so" and then say what you understand. Some examples include:

So Edgar is being promoted?

So I take a left at the next light and then take the third right after that?

Notice that these are in a statement form, not a question form. The question form would be:

Is Edgar being promoted?

Instead of putting it in question form, you start with "so" and use rising question intonation at the end of the sentence. If you ask in this way, the listener will understand that you're trying to check what you know.

In the example at top, the speaker thinks that they haven't filed for a divorce because there's a difference between separating from your husband or wife and getting a divorce. Separating is something that the couple decides and does on their own. A divorce is a legal process. So if you hear that someone "separated" from his wife, you might think that they haven't been legally divorced yet.