Their, there, and they're

their /THār/ pn. poss. belonging to them.

Proper use:
Right: "It was their turn to fly the kites."
Wrong: "Put the flower pot over their."
Wrong: "Their are 24 hours in a day."
Wrong: "I thought they were winning, but their losing."

there /THār/ adv. in, at, or on that place.
initiatory. a word used for the general existence of a thing or state of being.

Proper use:
Right: "Put the flower pot over there."
Right: "There are 24 hours in a day."
Wrong: "It was there turn to fly the kites."
Wrong: "I thought they were winning, but there losing."

they're /THār/ contraction. a contraction meaning they are.

Proper use:
Right: "I thought they were winning, but they're losing."
Wrong: "It was they're turn to fly the kites."
Wrong: "Put the flower pot over they're."
Wrong: "They're are 24 hours in a day."