it’s its, stupid.
it's
means "it is" (or "it has")
It's embarrassing how you acted in that meeting today.
its
pretty much every other application of the word
Be easy on the Xerox machine; its exterior is durable, but can only take so much.
now that we've cleared that up, make sure you know:
you're: means "you are"
You're terrible at cold calls, Mr. Bigby.
your: belonging to a person
Please remove your compact disc from the optical drive prior to shutting down for the evening.
they're: means "they are"
They're going to come over for olives and chips in the board room to discuss fonts for our newsletter.
there: a place or position
I need you over there in the lunch room, we're about to sing happy birthday to Doris.
a reference to something that exists
I encourage you to participate in the team building exercise after work; there will be snacks.
their: belonging to people or things
Can you page the marketing team? We need their opinion on these spreads.