什麽是雙賓語和形式主語
英語中, 有些及物動詞可以接兩個賓語，即指人的間接賓語和指物的直接賓語，這兩個賓語稱為"雙賓語"。句子結構為："主語＋及物動詞＋間接賓語＋直接賓語"。如：
My parents bought me a computer. 我父母給我買了壹臺電腦。
雙賓語用法要點：
1、間接賓語可以改為由介詞to或for引起的短語, 放在直接賓語後面。如：He gave her some chips. = He gave some chips to her.
2、以下幾種情況通常要用介詞to或for引起的短語：
1)當直接賓語是人稱代詞(it/them)時。如：This book is Mr Wang’s. Please give it to him.
2)當強調間接賓語時。如：Mother cooks meals for us every day.
3)當間接賓語比直接賓語長壹些時。如：On the bus, she often gives her seat to the old person.
3、由to引出間接賓語的動詞有：give, show, pass, lend, take, tell等；由for引出間接賓語的動詞有：buy, make, cook, get, sing, read等。
形式主語
當代英語中, 通常用it 做形式主語，將不定式和動名詞置於謂語後面，特別是主語較長時，或在壹些習慣用法中。
1）謂語是系表結構（be + 形容詞 / 名詞）時，常將不定式後置，構成句型 “it + be + 表語（形容詞 / 名詞）+ 不定式”。
It is my duty to care for that patient. 照料那位病人是我的職責。（做主語的不定式to care for that patient 後置，it 為形式主語）
It is not an easy thing to master a foreign language. 掌握壹門外語不是件容易的事。
It isn’t right to speak ill of someone behind his back. 在別人背後說壞話是不對的。
2）當謂語是 take, make, pay, cost , require, feel, need 等動詞時，或者是與情緒有關的動詞 delight, amuse, excite, annoy, irritate 等時, 習慣上常用 it 做形式主語，並將不定式後置。
It takes only ten minutes to get there. 到那兒只需十分鐘。
It pays to be honest. 誠實是不會吃虧的。
It feels good to stay away from the crowded city. 能遠離擁擠的城市，感覺真不錯。
It annoyed her to see someone spit on the ground. 看見有人隨地吐痰讓她很生氣。
3）同不定式壹樣, 動名詞也可用於“it + be + 表語 + 動名詞”句型中。
It is a waste of time to argue with him
It is a waste of time arguing with him.
和他爭辯是浪費時間。
It is worthwhile to discuss this again.
It is worthwhile discussing this again.
這壹點值得在討論壹下。
4）但表語是（of）no use, not any use, not the slightest use, no good, not much good, fun等時，常用動名詞（不用不定式）做主語並後置，用 it 做形式主語。
It’s no use crying over spilt milk.覆水難收。