You'll need to go to the bank to buy some traveler's checks.

你得先去銀行買好旅行支票。

Our next lesson will give you a good idea of what you need to say and how to say it.

我們下一課會教你該說什麼和怎麼說。

上列句中, 使用了"need to + 原形動詞" (必須……)的句型。

在肯定句中, need為一般動詞, 有人稱和時態的變化, 其後可接名詞或不定詞片語 (to + 原形動詞)作受詞。

need + 名詞　　需要……

need to + 原形動詞　　必須……

例: She needs our help.

　 (她需要我們的幫助。)

　I need to go now.

　(我現在必須走了。)

　若某物『需要』某種方法處理時, need之後可接不定詞片語, 但一定為被動語態; 或接動名詞, 但一定為主動語態。

例: The door needs being fixed. (╳)

　→The door needs to be fixed. (○)

　　     　　　　   不定詞片語

　= The door needs fixing.

　　　   　　 　   動名詞

　(這扇門需要修理。)

　My car needs being checked. (╳)

　→My car needs to be checked. (○)

　　　　      　　　 不定詞片語

　= My car needs checking.

　　　　　　　　   動名詞

　(我的車子需要檢查一下。)

注意:

a. need與not並用時, need not視為助動詞, 無人稱和時態的變化, 其後直接置原形動詞。

need not + 原形動詞　　不必……

例: He needs not go. (╳)

　He need not to go. (╳)

　→He need not go. (○)

　= He doesn't need to go.

　(他不必去。)

　You need not pay this bill immediately.

　= You don't need to pay this bill immediately.

　(你不必馬上付這筆帳。)

b. 表過去狀況時:

didn't need to + 原形動詞　　當時不必……(而且亦未……)

need not have + 過去分詞　　當時不必……(但卻做了)

此兩種句法完全不同。第一種句法表示『過去的事實』, 而第二種句法則為『與過去事實相反』的假設語氣。

例: He didn't need to attend the meeting, so he stayed home.

　(當時他不必去開會，所以就留在家裡。)

　You need not have given me so much money.

　(你當時並不必給我這麼多錢。──但卻給了)

For example, you might want to know what the day's exchange rate is, or if there are any handling charges, etc.

比方說, 你可能想知道當日的匯率或者銀行是否收取任何手續費等等。

上列句中, what引導的名詞子句與if引導的名詞子句為對等連接詞or所連接, 共同作其前及物動詞know的受詞。此處的if即等於whether, 因whether引導的名詞子句在句中若作及物動詞的受詞時, 則whether可用if取代, 此時if譯成『是否』, 而非『如果』。

例: We don't know whether John and Mary will come to our party.

　= We don't know if John and Mary will come to our party.

　(我們不知道約翰和瑪麗是否會來參加我們的派對。)

　if若作『如果』解時, 是副詞連接詞, 引導副詞子句, 修飾主要子句。

例: If I have time, I will certainly help you.