1.If the weather *is* nice, I will go to the beach.
2. If the water isn't too cold, I *will go* for a swim.
3. If I *was* 18 years old, I *would drive* a car to school every day.
4. If there hadn't been a tornado, the houses *wouldn't have been destroyed*.
5. If I *had been shy*, I wouldn't have danced all night.