Raise and rise can both be verbs and nouns but, like lay and lie, as verbs one is transitive and the other is intransitive.
As a verb to rise is intransitive. This means that it doesn’t take an object. Things rise of their own accord. They don’t cause other things to rise. For example:
- She rises each day at six.
- He rose to an upright position.
- The people are rising up against their rulers.
Rise can also be a noun:
- The staff got a pay rise.
- The Rise and Fall of the House of Medici.
- Use of Twitter is on the rise.
Raise is a transitive verb which means that it requires an object. You have to raise something, even if it’s only yourself. For example:
- He raised himself up to standing.
- She raised her voice.
- Raise your glasses in a toast!
As a noun, raise only has limited use. My Concise Oxford Dictionary notes two uses:
- An increase in salary.
- An increase in a stake or bid whilst playing cards.