דבר דבר (Dabair Davar): Going to Visit a Sick Person on Shabbos. More About תהילים Tehillim and מי שברך Mi Shebeirach;
more examples of "מבטל כלי מהיכנו" (nullifying a vessel from its normal usage) that come up on Shabbos;
Giving a gift. (Understanding how that concept works).