Language tip of the week: reason

This week’s language tip helps with the noun reason:

After reason, use the preposition for, not of:
✗ The main reason of poverty is unemployment.
✓ The main reason for poverty is unemployment.
✗ A doctor can’t operate if he doesn’t know the reason of the illness.
✓ A doctor can’t operate if he doesn’t know the reason for the illness.

from the Macmillan Dictionary to English language learners