more careful&most careful??

首先要了解在問題中, more和most的分別
more, 是指「比較...」的意思, 只要有2樣東西的情況下便可以使用
most, 是指「最...」的意思, 通常是指一群人或東西中最...那的個/那位
要說某物件是「最...的」, 那至少也應該有3個物件聽起來才合理對吧?

例如:

>> more careful

John is more careful student than Mary.
(john是個比mary更小心的學生)
The floor is wet today. We need to be more careful.
(今天地面很濕, 我們要更小心)

>> most careful

Peter is the most careful person among us.
(peter是在我們之中最小心的人.)


希望可以幫到你^^

You should be more careful when come home at night.

Timmy is the most careful person in our class