"The" before a noun

The rules can get tricky

When both you and the person you're talking to know exactly which noun is being discussed. If you are standing next to a horse and you both can see it or you are both aware of it, you can say "Should I get on the horse?" Its also easy to use this rule for some instances...Can you point your finger at it? This only works soemetimes.

Also the second time you mention the noun use "the. For example. "I watched a movie tonight. The movie was pretty good."