Learn Hardcore Polish: Wczoraj taksówkarz znał dobry skrót, więc taksówka przyjechała na dworzec wcześniej. - Yesterday the taxi driver knew a good shortcut, so the taxi arrived at the station earlier.

Breakdown of Wczoraj taksówkarz znał dobry skrót, więc taksówka przyjechała na dworzec wcześniej.

Why does the sentence start with Wczoraj?

Polish word order is fairly flexible, so Wczoraj is placed first to set the time frame right away: Yesterday.

Starting with the time expression is very natural in Polish, especially when you want to establish the context before giving the main information.

You could also say:

But those versions shift the emphasis. The original sentence sounds natural and neutral.

Why is it taksówkarz, not some other form like taksówkarza?

Because taksówkarz is the subject of the first clause, and subjects are normally in the nominative case.

Here:

So taksówkarz znał means the taxi driver knew.

If it were taksówkarza, that would usually be an accusative or genitive form, and it would not fit as the subject here.

Why is the verb znał used here? Why not wiedział?