MB3 101a: Hiring Workers on Shabbos (307:1-3)

Even neutral conversation that serves no purpose but isn't negative should be avoided on Shabbos. How to greet people on Shabbos.

Hiring workers on Shabbos is prohibited even if the work won't be done until after Shabbos. Anything you can't do on Shabbos (even עובדא דחול), you cannot ask a non-Jew to do on Shabbos. Hinting to a non-Jew to do melacha for you on Shabbos.

Giving a non-Jew money to buy something on Shabbos.