Examples

He is a substitute for Jeff. He's the undoubtedly jittery subject of the sentence who does the drinking. And that way, the sentence does read like this: "Jeff can't start his day without caffeine, so Jeff drinks three cans of Mountain Dew every morning for breakfast." Not quite as tidy.

Did you know there are 17 different varieties of Mountain Dew? Our favorite is Passionfruit Frenzy, which you can only get in New Zealand.

I is the subject of the sentence; it stands in for the name of the absentminded pet owner who lost a pet. Me is the object of the sentence. It stands in for the name of the person who also received a free slice from Mitch, the best friend ever.

They replaces Manchester United, which is the subject of the sentence because they did the winning. They always do the winning. Maybe that's why they can count Justin Timberlake, Megan Fox, and Orlando Bloom among their famous fans.