Suppose/Supposing (that) ...

　　結構┱Suppose/Supposing (that)+子句，S+V ...

　　說明┱此句型意為“如果…，假使…”。Suppose/Supposing (that) 引導假設條件句，其功能相當于 if。

　　Suppose/Supposing (that) we miss the train, what shall we do?

　　如果我們誤了火車，我們將怎么辦?

　　What if/Say ...

　　結構┱What if/Say+子句，S+V ...

　　說明┱此句型意為“假設…”。What if 和 Say 用來引導一個假設條件句，其義相當于 Let us suppose(讓我們假設)。

　　What if/Say he goes home before us and can’t get in? What will he do then?

　　假設他在我們之前趕到家而又進不去呢?那他怎么辦呢?

　　What if/Say you were to run out of money? What would you do?

　　假設你的錢用完了呢?你將怎么辦呢?

　　With luck ...

　　結構┱With luck，+主要子句

　　說明┱With luck 為含蓄假設條件句(即不用 if 直接引導)。with luck 意為“如果幸運的話，如果運氣好的話”。

　　With luck, we’ll be there by tomorrow.幸運的話，我們明天將到達那兒。(=If we are lucky)

　　With luck, she will get the job. 如果幸運的話，她將得到那份工作。(=If she is lucky)