than用于比较,而比较必须是同类人物进行比较|(经常是和句子的主语进行比较)。
I‘m taller than you.
= I'm taller than you are.
My room is bigger than yours.
= My room is bigger than yours is.
= My room is bigger than your room is.
I get better grades than he does.
= I get better grades than he.
does代指前面的gets grades这个动作
这也要看情况,人和人比,物和物比,至于省略的,就拿第二句说,应该是跟your room的,但用yours代替了
后面接名词