As soon as S + V, S + V
The moment S + V, S + V
The instant S + V, S + V
The minute S + V, S + V
Once S + V , S + V
Directly S + V , S + V
Immediately S + V , S + V
Instantly S + V , S + V
At + n. , S + V ß前後主詞相同時
on / upon + Ving , S + V ß前後主詞相同時
As soon as I left home this morning, the phone rang
The moment I left home this morning, the phone rang
The instant I left home this morning, the phone rang
Once I left home this morning, the phone rang
Directly I left home this morning, the phone rang
1. as soon as 為連接詞，引導副詞子句，修飾主要子句
As soon as I saw her, I knew there was something wrong.
這句主要是要表示有什麼事情不對勁，as soon as引導的看到她只是用來修飾什麼時候覺得不對勁。
2.用在未來時態上，as soon as 引導的副詞子句是條件句，故應採現在式，主要子句採未來式
As soon as S + 現在式V, S + will + V
As soon as he gets home, he will take a shower. (他一回家就會洗澡)
3. On/Upon + V1-ing, S + V2 . . . 僅可使用於前後的主詞相同之時
Upon arriving in Taipei, I will give you a call. (一抵達台北我就會打電話給你)
As soon as my mom left, my little brother began to cry.
On leaving, my little brother began to cry. (X) 此為錯誤用法
S + had + no sooner + Ved/3 than + S + Ved/2 ß比較級sooner後面連接詞用than
= S + had
S + V
They had hardly got to school when they began to study.
The had scarcely got to school before they began to study.
Scarcely + had + S + Ved/1 when + S + Ved/2 ß倒裝句
Hardly + had + S + Ved/1 when + S + Ved/2
No sooner + had + S + pp than S + V
注意No sooner had + S1 + V1-en + than + S2 + V2-ed前後句的時態不同。該句型的前半部表示先發生的事，即「一…」的部分，使用過去完成式had V-en；後半部表示接著發生的事，即「就…」的部分，使用過去式V-ed，例：
Hardly/Scarcely had they got to school when/before they began to study.