is a verb and sale
is a noun:
- I'm going to sell
my car and buy a new one.
- She's selling bottles of water at the football game.
- Yesterday I sold all of my old college textbooks on the internet.
- The bookstore is having a Christmas sale
- everything is 20% off. (20% off = 20% discount)
- The sales of our new product are slowly increasing.
- This watch is normally $100, but it's on sale for $70.
(on sale = there is a discount)