That vs. Who
Wrong: People that act superior annoy me to no end.
Right: People who act superior annoy me to no end.
Wrong: I hate referees that mess up a penalty call.
Right: I hate referees who mess up a penalty call.
Right: Jets that operate via fly-by-wire are inherently unstable.
When referring to people, use who. When not referring to people (inanimate objects, animals, insects, etc.), use that.
Waited(ing) on vs. Waited(ing) for
Wrong: He waited on her for more than an hour!
Right: He waited for her more than an hour!
Unless you’re referring to a food server who waits on customers, the correct expression is waited for someone, not waited on them.
Want more? I'm afraid you'll have to wait until next time.