這句的grammar是否正確?

正確

He had a gun with which to defend himself. = He had a gun to defend himself with.
只是將with移上前就要加which連接, 意思亦比較放重在 He had a gun.

這句子之前是不是在敍述他有的其他物件? 如果是, "also" 就合理了.
He had.........He also had a gun with which to defend himself.
這樣就是主要說他還有一把槍, 補充說明是用來自衛的

I agree with 小草, but can we just say: "He also had a gun to defend himself." ?

He also had a gun with which to defend himself.
這句 grammar 正確。

英文句子中，將 preproposition 放在 relative pronoun 前是普遍的。

“with which to defend himself” 是 phrase，所以只有 to infinitive 是可以的。

句子中的 also 並非文法不容許，但這句子不應獨立出現，應有「上文」去配合“also”。

He also had a gun with which he defended himself.

equivalent to

He also had a gun, he defended himself with the gun.

He also had a gun with which to defend himself.

Should read as following with same meaning:
He owns a gun which using to defend himself.

Note: also 這字在此單句中並無比較詞, 故不應用.


2012-05-11 13:15:13 補充：
Note: also 這字在此單句中並無比較詞, 故不應用.

Unless:
He had a knife also had a gun to defend himself.

2012-05-12 10:40:57 補充：
小草( 大學級 1 級 )
100% agreed with your opinion. Best answer if posted.

error and correction;-
He also had a gun(to defend himself) with.
=which is used to defend
=adjective clause(gun)
=used to give more information about the gun
=used to be exact usage about the gun that you mean
=to defend himself.
---(with)=preposition.
used in question Sir Winston Churchill once asked,
This is the kind of English up (with which) I'll not put.
----(put)=preposition.

不正確
Which 之後應該先加Verb
所以應該是He also had a gun with which is to defend himself.