5. He studied Maths worse than Tu

-) Tu........................

6. We will service at the airport earlier than Hoa

-) Hoa.....................

7. The buses run more frequently than the train 

-) The train....................

`5)` Tu studied Maths better than him

`6)` Hoa will service at the airport later than us

`7)` The train run less frequently than the buses

`@` worse `(` tệ hơn `)` `><` better `(` tốt hơn `)`

`@` earlier `(` sớm hơn `)` `><` later `(` muộn hơn `)`

`@` more frequently `(` thường xuyên hơn `)` `><` less frequently `(` ít thường xuyên hơn `)`

`**` một từ từ `2` âm trở xuống thêm "er" vào cuối chữ và "than" khi so sánh hơn 

`**` một từ từ `2` âm trở lên thêm "more" hoặc "less" ở trước và "than" ở sau để so sánh hơn

5. Tu didn't study Math as badly as he did.

6. Hoa won't service at the airport as early as we will. 

7. The train doesn't run as frequently as the buses do.

``

So sánh ngang bằng (trạng từ):

S1 + V + not as + adv + as + S2