1. 在下列情況，其后通常不接介詞 into：

(1) 表示進入某一具體的東西時：

The train entered the tunnel. 火車進入隧道。

She entered the room without knocking. 她沒敲門就進了房間。

The bullet entered his head. 子彈射入他的頭部。

(2) 表示進入某一組織或某一機構時：

He entered the army last year. 他去年參軍了。

Then he entered a famous university. 后來他進了一所名牌大學。

(3) 表示報名參加考試(比賽等)時：

All his friends entered the examination (race). 他所有的朋友都報名參加了考試(比賽)。

She not only entered the competition she actually won it! 她不但參加了競賽——而且居然獲勝了!

Although he had only entered the contest for fun, he won first prize. 盡管他參加這次競賽只不過是鬧著玩兒而已，卻贏得了頭獎。

2. 下列情況，enter 后通常接介詞 into：

(1) 開始(做某事)

I dared not enter into conversation with him. 我未敢與他交談。

He entered into business at the age of 25. 他25歲時開始經商。

(2) (開始)討論，研究，處理

Let’s enter into the subject of taxes. 咱們來討論一下稅款問題。

We need not enter into details. 我們不必討論(研究、處理)細節。

(3) 積極參加，參與，投入

He entered into our plans with terrific zest. 他滿腔熱情地參加了我們的項目。

The party was successful because everyone entered into the spirit of the thing. 這次聚會因大家積極參與所以很成功。

(4) 達成(協議)，締結(條約)

We entered into a solemn bond. 我們締結了一項正式協定。

You shouldn’t enter into contract until you have studied its provisions carefully. 你應該先仔細研究合同的條款，然后再簽訂。

(5)(不用于被動語態)形成某事物的一部分：

This possibility never entered into our calculations. 我們從未考慮過有這種可能性。

Flour has largely entered into their diet. 面料已成為他們的主食之一。

(6) 懂得，領略，體會，理解：

He didn’t enter into her mood. 他不體諒她的心情。

I can enter into your feelings at the loss of your wife. 我能理解你失去妻子后的心情。

(7) 表示進入某具體東西且強調深入其內時(若不強調則可不用)：

The arrow entered into his head. 箭射進了他的頭。

We entered into a woody mountain. 我們進入了一片山林里。