3. Big, bigger, the biggest
4. Weak, weaker, the weakest
5. Tall, taller, the tallest
6. Short, shorter, the shortest
7. Thin, thinner, the thinnest
8. High, higher, the highest
9. Low, lower, the lowest
10. Heavy, heavier, the heaviest
11. Light, lighter, the lightest
12. Young, younger, the youngest