英文文法問題~! Thx~

1. 原則上呢條無答案(因為句子唔完整)，我就當成句係 "This is important mainly because of the words in this message."
"mainly because of..." 係一舊野，所以mainly係講緊"because of..."，假如mainly講important，句子解唔通。

2. 呢句有問題。"while"後面固然可以跟gerund(-ing)，問題如果照上面句句子，
一. 無subject (while I eff... identify and attract/ it eff... identifIES and attractS/ etc.) 二. 唔想出subject，可以用gerund，問題呢度都僚 (while eff... identifyING)

3. 成句錯。that後面係一個新句子，要有subject，呢到無。
that係呢到(HERE ONLY!!) 係一個名詞子句嘅起點 (subordinating conjunction)，不過您唔係專讀Grammar唔駛理，記住佢係一個連接詞就得架啦。幾時落就... 睇多d英文書，您就會知邊度落/唔落 成句睇/讀起會順d。

4. I love (V1) swimming (V2), sleeping (V3) and swimming (V4).
睇完呢句明唔明？
一個句子只有一個正動詞 (main verb)，之後嘅動詞要全部轉做 to-infinitive (to do), base form (do) or gerund (doing)，咁假如您所有想講嘅野都係跟個love嚟轉，咁comma 後面都係-ing.

或者您可能指呢一款野：Hearing someone screaming, I got out of my bed.
呢d -ing係present participles，講原因，時間。
原因：Being unwell, I took a day off. (= Because I was unwell, I took a day off.)
時間：She hurt her legs playing baseball. (= While playing baseball, she hurt her legs.)
He stood there waiting for her girl-friend. (= He stood there and waited for her girl-friend.)
Hearing someone screaming, I got out of my bed. (= After I heard someone screaming, I got out of my bed.)
HAVING CHECKED my homework, I handed it in. (= After I had checked my homework, I handed it in.)
呢d -ing唔一定要係逗號後面。

2014-02-03 03:22:29 補充：
不過(1) 其實唔駛成句都知mainly一定係講because of，因為講important係解唔通.