IELTS Grammar: is, will, would, would have

Compare the following sentences. Can you explain the difference in meaning between each one, or suggest when we might use each one?

1) This book is useful.

2) This book will be useful.

3) This book would be useful.

4) This book would have been useful.

Comments

[Muhammad Imran Asif]

1)This means that it is definitely useful.
2)This means that it is useful but later on.
3)This means that it might be useful or it might not be.
4)This means that it might have been useful in the past.

[esam]

1 from my opinion , this book is definitely useful
2 from my point of view , this book will be usefull in the future in upcoming practise
3 the book may be useful .. it is a matter of probability
4 the book may have been useful in the past .. a matter of probability and also in the past

[Ziaul]

1) This book is useful.
- it is clearly useful.

2) This book will be useful.
- useful in future.

3) This book would be useful.
- It is useful for any person(Polite request)

4) This book would have been useful.
- Useful in the past ( But it didn't use)

[Daljeet Kaur]

1. book is useful (in present its 100% true)
2. book will be useful in future (100% certainty)
3. Book would be useful(50% possibility/ may or may not be)
4.This book would have been useful (past hypothetical situations)

[Shyiwa]

1) This book is useful. -> A present statement

2) This book will be useful. -> A judgement for the future.

3) This book would be useful. -> A suggestion? Very sincerely.

4) This book would have been useful. -> Hmmmm, if you used this book, this book would have been useful. (BUT YOU DIDN'T!!!)

BTW, I want to thank you Simon to help me not only on the IELTS test but also daily work now. The writing guidance is rather useful for both writing and improvise presentation, simultaneously enhancing one's analytical techniques which is lack among most Chinese students.

[sujit kumar biswas]

1. This book is useful---Pesent
2. This book will be useful. useful in the future
3.This book would be useful.same like will be
4.This book would have been useful. It might be happen but didn't happen.

Thank you simon as always

[Ronie Siddiky]

1) This book is useful. -- the speaker makes a general statement.

2) This book will be useful. -- the speaker suggests someone to read the book as it is useful (certain).

3) This book would be useful. -- the speaker suggests someone to read the book but uncertain about the usefulness of the book (uncertainty).

4) This book would have been useful. -- the speaker suggested someone, if s/he read the book in the past it was useful but s/he didn't do it.

[Hessam]

is useful = present statement/ fact
Will be useful = statement about future 100%
Would be = may be useful. May be not ! Although tends to be more positive, it is not 100%

Would have been useful = it had the potential to be useful, but the necessary conditions didn't meet the criteria

[Simon]

ANSWERS FROM SIMON:

Please read my explanations carefully, because some of the students' answers above are not quite correct.

1) I know that the book is useful. Maybe I have used it before, or I'm using it now. I can definitely recommend it.

2) I intend to use the book in the future, and I am sure that it will be useful. Or I'm recommending the book to someone i.e. you should use this book because it will be useful for you.

3) THIS IS THE TRICKY ONE!

The word "would" implies a condition (if...). For example, "this book would be useful if I had it or if I bought it". Imagine you're in a bookshop looking at the book, and you think to yourself: "Hmmm, if I bought this book, it would be useful". In other words, I'm considering buying the book because it looks useful.

Another possibility is that you are recommending the book to someone else: "You should use this book, because it would be really useful for you (if you did)".

NOTE: "this book would be useful" DOES NOT MEAN "it might be useful or it might not"!

4) This sentence is imagining a different past i.e. I didn't read the book, but I can now see that it would have helped me (if I had read it).

[Nam Anh]

Thank you, Teacher Simon!

[lana]

Simon for the tricky one: What is the difference between the full conditional you wrote and this one: If I buy the book, it will be useful(supposing the same that I am at the library seeing the book which looks useful)
Because what I understand from your using of the second conditional form is that I am not intending to buy the book (not: intending to buy it?

Please clarify this

[Philip YANG]

The 3rd and 4th sentence are the second and third conditional sentence respectively(subjunctive).

second conditional:

present:
If+ Subject+ were/V(past form), Subject + would/should/could/might + V (original form)

future:
If+ Subject + were to + V(original form), Subject + would/could/should/might + V(original form)

third conditional:

past:
If+ Subject + had + V(past participle), Subject + would/could/should/might + have + V(past participle)

[Simon]

lana,

When I use 'would' (second conditional), I'm imagining, so there is much less certaintly about whether or not I will buy the book. So you're right: I wasn't intending to buy it, but now I'm considering it.

[Corey28]

Hi Simon,

My answer as below:

1) This book is useful.

This is a fact statement in the present or even in the future maybe, depending on the context.

2) This book will be useful.

This statement refers that this book is useful merely in the future.

3) This book would be useful.

This sentence based on imaginary cases, conditional statement, which it's not necessarily to be true unless something happened.

4) This book would have been useful.

For this statement, it's only true in the past if something had happened. In other words, it's impossible to be true or achieved at present as it's for finished events.

Cheers!
Corey