A sentence has a telling part. Sometimes a sentence has two telling parts with different or opposite ideas.
These telling parts can be joind with the word but.
A comma (,) is usually used before the word but.
![monkey](https://smrt.sfo2.cdn.digitaloceanspaces.com/core/LMLA/KIDS/ENGL110Kids/unit08/Grammar%208-2/8-2g1.jpg)
This monkey likes to swing, but doesn't like to swim.
![friend](https://smrt.sfo2.cdn.digitaloceanspaces.com/core/LMLA/KIDS/ENGL110Kids/unit08/Grammar%208-2/8-2g2.jpg)
We can be happy, but our friends can be sad.
![boy](https://smrt.sfo2.cdn.digitaloceanspaces.com/core/LMLA/KIDS/ENGL110Kids/unit08/Grammar%208-2/8-2g3.jpg)
The boys are hungry, but they are also sleepy.