Why would he omit "th-" and only say "'em?" Is it a common way to say "them?"

Rebecca

Yes, that's correct! In colloquial English, many people drop the "th-" sound at the beginning of "them," to say "em" instead! It's very common to say it like this in casual conversation. Ex: I heard you bought new shoes! How do you like 'em? Ex: Don't listen to 'em. They don't know the full story.