1. that 用作形容詞，複數為 those
What’s about that book I have lent to you last week?
that little daughter of John （約翰那寶貝小女孩）
that Tom! （湯姆這傢伙!）
2. that 用作代詞:避免重複，代替前述名詞。
The price of oil is higher than that of wheat.
3. that 用作【關係代詞】:帶出限制性子句（defining clause）, 用法相當於who/whom/which
He is now talking about the man that（who） has just met.
This is the most wonderful movie that （which）our company has ever produced.
The woman that（whom） you’ve just met is my mother.
如在defining clause 中，that 作Object（受詞）的話，that 可以省略掉，如上面有兩句可寫成:
This is the most wonderful movie our company has ever produced.
The woman you’ve just met is my mother.
4. that 用作【連接詞】:帶出名詞子句。
I expect that we would win.
That you learn English takes time.
The trouble is that we lack communication.
5. that 用作【同位語子句】
The news that she finally resigned surprised us.
The idea that he supports is prevailing （流行）in this new generation.
6. that 用作狀語子句。
Please bring it closer that I can see clearer.
I am afraid that I will fail in the exam.
7. that 用作副詞
I am that/so angry I could have punched him!
8. that 用作【關係副詞】:帶出限制性子句，用法相當於when, where, why, in which
I won’t forget the evening that(when) we had our first kiss.
I won’t forget the house that （where/ in which ）we lived together.
9. 與that 相關的常見短語
a. in that （可譯:因為）
Criticism and self-reflection is sometimes necessary in that they help us correct our mistakes.
b. now that （因為【必須是現在/現在完成式】）
Now that he has gone bankrupt, I decide to abandon the claims.
c. see to it that （務必注意做到）
we will see to it that all staff should come on time.
d. seeing that （鑒於）
Seeing that he had been bankrupt, I decided to abandon the claims.