Conditional Sentences

Conditional Sentences *Generall y speak ing , con diti onal sentences 由以下句型組成 : IF cla use (hypo thesis) + MAIN clause (re sul t) 如果 if-clause 是在 main clause 的前面, 兩組 clauses 由 comma ( , )來分隔. 然而, 如果 main clause 寫在 if-clause 前, 則無需以 comma ( , )分隔. e.g. If I see Tracy, I will give her her pen. I will give Tracy her pen if I see Tracy. *use un less instead of if... not in the if-clause of Type 1 cond itio nals. (note that: the verb is always in the affirmative after unless.) There are 4 types of conditionals sentences,

Type 0

If-clause (hypothesis) If + present simple

General

If the temperature fal ls below 0°C, water tu rns int o ice.

truth Type 1

If + present simple, present perfect, present continuous, present perfect, present perfect continuous

Real present

Main clause (result) Present simple

future/imperative can/may/might/must/should/c ould

Use Something which is always true

Real – likely to happen in the present or future

+ bare infinitive If he doesn’t pay the fine (n.罰款), he will go to prison. If you need help, come and see me. If + past simple / past would / could / might continuous + bare infinitive

Type 2 Unreal present

1)

Imaginary situation contrary to facts in the present

2) Give advice If she had time, she would help us (but she doesn’t have time – untrue in the present)

Type 3 Unreal past

If I were you, I would not go to shopping. (giving advice) If + past perfect / Would/could/might past perfect + have + past participle continuous

1)

Imaginary situation contrary to facts in the past

2)

Express regrets or criticism

If I had studied harder, I would have passed the exam. http://www.xanga.com/private/home.aspx?user=class_4F5F_language_blog

Conditional Sentences What is also worth mentioning is that, *We can use

If I were you

... to givi ng advice

*Replac ing if The following expressions can be used instead of if • • • • • • • • •

provided e.g. You can see Miss Leung provided you have an appointment. providing that e.g. We will start our meeting providing Mary comes on time. as long as assuming (that) on condition (that) on the assumption (that) supposing (that) unless with the condition (that)

*Omitt ing if 當 if 在 if-clause 中被省去, 主詞(subject)及 auxiliary verb (should (Type 1), were (Type 2), had (Type 3))則應倒置. e.g. Should Mary arrive, tell her to hand in the homework. (If Mary should come...) Were I you, I would not tell him. (If I were you...) Had he listened to me, he would have done. (If he had listened to me...)

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