-est

1) My brother is tallest in my class

2) This car is cleanest in this street

3) This book is biggest in my collection

4) This pen is oldest in my pencilcase

5) Saturn is biggest planet in solar system

-er

1) My brother is taller than me

2) This car is cleaner than that car

3) This book is bigger than this book

4) This pen is older than this pen

5) Saturn is bigger than the Pluto