Unit 9: Conditionals
Ngữ pháp Conditionals: zero, first, second, third, mixed, inverted / unless, in case, as/so long as, provided (that)
📘 Giải thích tiếng Việt
Câu điều kiện loại 0 (Zero conditional)
Hình thức: if + hiện tại đơn, hiện tại đơn. Dùng cho sự thật hiển nhiên, quy luật khoa học hoặc định nghĩa. Ví dụ: If you heat ice, it melts.
Câu điều kiện loại 1 (First conditional)
Hình thức: if + thì hiện tại, will + động từ nguyên mẫu. Diễn tả điều kiện có thật hoặc nhiều khả năng xảy ra ở hiện tại/tương lai. Có thể thay will bằng may, might, can, could, should… để đổi sắc thái (khả năng, lời khuyên).
Câu điều kiện loại 2 (Second conditional)
Hình thức: if + quá khứ đơn, would + nguyên mẫu. Diễn tả điều kiện không có thật, khó xảy ra hoặc giả định ở hiện tại/tương lai. Dùng If I were you… để khuyên (trang trọng hơn was).
Câu điều kiện loại 3 (Third conditional)
Hình thức: if + quá khứ hoàn thành, would have + phân từ II. Nói về giả định trái với quá khứ và kết quả trong quá khứ. Ví dụ: If you had worn a beard, no one would have known.
Điều kiện hỗn hợp (Mixed conditionals)
Kết hợp hai mốc thời gian: quá khứ hoàn thành ở mệnh đề if nhưng kết quả ở hiện tại (would + nguyên mẫu), hoặc điều kiện hiện tại nhưng kết quả trong quá khứ (would have + phân từ II).
Câu điều kiện đảo ngữ (Inverted)
Dạng trang trọng, lược bỏ if: Should you… (loại 1), Were you… (loại 2), Had you… (loại 3). Ví dụ: Had the situation worsened, the UN would have acted.
unless, in case, as/so long as, provided (that)
unless = 'nếu… không / trừ khi'; in case = 'phòng khi (vì có thể…)'; as/so long as và provided (that) = 'miễn là / chỉ khi'. Lưu ý sắc thái: in case chỉ hành động đề phòng trước, khác với if chỉ nêu điều kiện.
Theory
Zero conditional
Form: if + present simple, present simple
| Use | Example |
|---|---|
| General or scientific facts and definitions | If you have faith in something, you believe in something you cannot prove. |
First conditional
Form: if + a present tense, will + bare infinitive
| Use | Example |
|---|---|
| Real or likely conditions in the present or future and their results in the present and future | If you have a birthday party, you'll get loads of cool presents! If you're working till half past six, we'll have dinner at about eight. If you have revised properly, you won't have any problems in the test next week. |
Watch out!
- We can also use may, might, can, could, shall, should, ought to, have to instead of will, depending on the meaning.
- We can also use should + bare infinitive instead of present simple. This suggests the situation is possible, but unlikely to happen.
If you should bump into Alex at the concert, you'll be able to get a lift home. - We can also use a form of the first conditional to give instructions: if + a present tense, imperative.
If you decide to have a birthday party, tell me!
unless, in case, as/so long as, provided (that)
| Word or Phrase | Meaning | Example |
|---|---|---|
| unless | 'except if' or 'if … not' | I'll be there at six unless I get delayed. (= except if I get delayed) |
| in case | 'because he/she/it/etc might' | Let's take our wellies in case it's muddy. (= because it might be muddy) |
| as/so long as | 'if' or 'only if' | As long as I'm happy, my parents don't care what job I do. |
| provided (that) | 'if' or 'only if' | Provided (that) I'm happy, my parents don't care what job I do. |
Second conditional
Form: if + past simple or past continuous, would + bare infinitive
| Use | Example |
|---|---|
| Impossible, unlikely or hypothetical conditions in the present or future and their results in the present or future | If you had a beard, you would look just like Charles Dickens! If you were flying to Rio, would you get there much quicker? |
| Advice | If I were you, I would think very carefully about my future. (more formal) If I was you, I'd have a party at the weekend! (more informal) |
Watch out!
- We can also use might or could instead of would, depending on the meaning.
If we were older, we could go on holiday on our own. - We can also use could in the if clause. Here, it means was/were able to.
If I could drive, I'd buy a car.
Third conditional
Form: if + past perfect (simple or continuous), would + have + past participle
| Use | Example |
|---|---|
| Hypothetical conditions in the past and their results in the past | If you had worn a fake beard, no one would have known who you were! If she'd been wearing her new glasses, I would have noticed them. |
Watch out! We can also use might, could or should instead of would.
If I had done some revision, I might / could / should have passed the exam.
Mixed conditionals
Form 1: if + past perfect (simple or continuous), would + bare infinitive
| Use | Example |
|---|---|
| Hypothetical past condition and a present result | If I had listened to my parents, I wouldn't be in so much trouble now. |
Form 2: if + past simple or past continuous, would + have + past participle
| Use | Example |
|---|---|
| Hypothetical present condition and a past result | If I had a mobile, I would have called you last night. |
Inverted conditionals
Form:
- Should I/you/he/etc … instead of If I/you/he/etc should …
- Were I/you/he/etc … instead of If I/you/he/etc were …
- Had I/you/he/etc … instead of If I/you/he/etc had …
| Use | Example |
|---|---|
| More formal form of the first conditional (with should) | Should the situation worsen, the United Nations is prepared to send in a peacekeeping force. |
| More formal form of the second conditional | Were the situation to worsen, the United Nations would be prepared to send in a peacekeeping force. |
| More formal form of the third conditional | Had the situation worsened, the United Nations would have been prepared to send in a peacekeeping force. |
Watch out!
- For all conditional sentences, when the condition comes before the result it is usually followed by a comma. When the result comes first, no comma is necessary.
- In conditional sentences, modals (will, would, could, etc) are sometimes followed by a continuous infinitive.
We'd still be waiting if you hadn't turned up.
Exercise A
Write Yes or No to answer the questions about each sentence.
Is it possible that Carl won't come to the party?
Is it likely that the neighbour will become prime minister?
Is Helen here now?
Did Tarek have enough money?
Did Debbie go to the UK?
Did the police investigate the case thoroughly?
Did she go to university?
Exercise B
Complete the definitions using your own ideas. (Use the zero conditional.)
Example: If you trust someone, you believe that they won't let you down.
Exercise C
Complete using the correct form of the verbs in the box.
Exercise D
Circle the correct word or phrase.
Exercise E
Write sentences using the second conditional.
Example: I don't want to buy that CD so I'm not going to. → If I wanted to buy that CD, I would.
Exercise F
Read the text and complete the sentences using the third conditional.
Some scientists, such as Stephen Hawking, believe it's possible that there are billions and billions of universes. Each universe has a different possible consequence for every action. In the universe we live in, for example, George Bush became President of the USA in January 2001, and Greece won the European Cup in July 2004. But in other universes different things happened. Imagine if that's true! In some universes, your parents didn't meet, so you weren't born. In another universe, a meteor didn't strike the Earth, so the dinosaurs didn't become extinct. In a different universe, your best friend won the lottery last summer and moved to a bigger house. In another parallel universe, you started learning English a year earlier, so you did this book last year! Somewhere else, Madonna wasn't discovered, and so didn't make any records. In another universe, Van Gogh was recognised as a great painter during his lifetime, and so didn't die in poverty. And perhaps in several universes, there were enough lifeboats on the Titanic and so everyone on board survived. It makes you think, doesn't it?
Exercise G
Choose the correct answer.
If this theory about parallel universes (1) __________ correct, it (2) __________ that we're living in more than one universe at the same time. But if that (3) __________ true – if I was doing different things in different universes – (4) __________ about it. And if I (5) __________ about it, how could it be me doing these things? If I (6) __________ the lottery last year in a parallel universe, and decided to sail round the world, how is that 'me'? It doesn't make sense!
And another thing. If I do something, it (7) __________ consequences. For example, if I (8) __________ study, I might not pass my exams. I can't start thinking about different universes where the consequences are different. If I just (9) __________ about the universe I actually live in, then I'm sure (10) __________ okay!
Exercise H
Complete using the correct form of the verbs in brackets.
Exercise I
Complete the sentences so that the meaning remains the same. Use inverted conditionals.
Should …
Should …
Were …
Were …
Were …
Had …
Had …
Exercise J
If a line is correct, put a tick (✓) next to the number. If there is an extra word in a line, write it next to the number.
Being an only child
1 I'm an only child. People often say to me: 'Wouldn't you be a lot 2 happier if you have had brothers and sisters?' but I don't see it like that. 3 It's true that if I had had a brother or sister, I would have someone closer 4 to my own age to talk to and play with at home, but I don't think that's 5 very important provided for you have close friends, which I do. If my 6 parents would had more children, they wouldn't be able to spend so much 7 time with me. And we have great fun together! Also, except if I had a 8 brother or sister, I'd have it to share a bedroom with them. That might be 9 fun, but what would happen if I wanted to play my CDs and he or she had 10 to study? No – I don't want a brother or sister, unless it will happens, of course. In that case, I'll think it's the best thing in the world!
