If it’s one of her favorite activities to do, then Crystal likes dancing.
If Crystal likes dancing, then it’s one of her favorite activities to do.
Not true: Someone can like dancing but it doesn’t necessarily mean that it’s their favorite activity to do.
If there’s a hurricane, then the store is closed.
If the store is closed, then there’s a hurricane.
Not true: The store could’ve been closed because it needed repairs.
If there’s snowfall, then snowflakes are going to fall
If snowflakes are going to fall, that means there’s snowfall
True: If it snows, it’s called snowfall because snow falls as precipitation from the sky when the temperature outside is low enough.