$\text{* short, tall.}$

$\text{- Nam is shorter than Nghia.}$

$\text{- Nghia is taller than Nam.}$

$\text{* old , young.}$

$\text{- My grandmother is older than my father.}$

$\text{- My father is younger than my grandmother.}$

$\text{* big, small.}$

$\text{- This buiding is bigger than that building.}$

$\text{- That buiding is smaller than this building.}$

1, I am shorter than my friend.

2, My mother is taller than me.

3, My father is older than my brother.

4, My sister is younger than my teacher.

5, I'm the biggest in my class.

6, My pencil is smaller than yours.