Raise or rise?

Raise must have an object, as it is a transitive verb. It is a regular verb; its three forms are raise, raised, raised:

• Raise your hand if you know the answer.
• Our favourite restaurant has raised its prices again. It's getting very expensive.

Rise does not take an object, as it is an intransitive verb. It is an irregular verb; its three forms are rise, rose, risen:

• The sun rose at 5.30 this morning.
• Rents have risen sharply in this part of town.