` So sánh hơn ` 

` 1 ` âm tiết : adj + er + than

` 2 ` âm tiết : more +adj + than

Good ` -> ` better

Bad ` -> ` worse

Far ` -> ` farther

` I ` 

` 1 ` : Safe ` -> ` safer

` 2 ` bad ` -> ` worse

` 3 ` dangerous ` -> ` more dangerous

` 4 ` modern ` -> ` more modern

` II `

` 1 ` : better than

` 2 ` : slower than

` 3 ` : prettier than 

` 4 ` : more expensive than

` 5 ` : cleaner than 

`I`

`1` safe -> safer

`2` bad -> worse

`3` dangerous -> more dangerous

`4` modern -> more modern

`II`

`1` better than

`2` slower than

`3` more pretty than

`4` more expensive than

`5` cleaner than

`->` So sánh hơn 

`+)` S1 + tobe + adj-er + than + S2 - adj ngắn

`+)` S1 + tobe + more adj + than + S2 - adj dài