difference between "don't need and needn't"?

Question

Would you please explain me the difference between "don't need and needn't"? with suitable examples?Also I would be obliged if I am given examples as to how its in Spanish.Would be waiting!!

"I will be waiting" is slightly more correct -- estaré, not estaría! - NancyGrace, May 24, 2011

But if I'm not wrong Nancy,"would" is used in english to signify politeness.Isn't it? - debadean, Jun 1, 2011

Yes, my dear deba, it is considered polite, but you have already been polite by saying "I would be obliged . . .". It is not necessary to be polite in the next sentence, also! - NancyGrace, Jun 1, 2011

Answer 1

Very simply put, deba:

There is a subtle difference:

Don't need (do not need) Is not necessary

Needn't (need not) Shouldn't have

The Spanish examples above are all good.

Yes "needn't have" puts the "need" into past - just like a Modal + the present perfect - ian-hill, May 24, 2011

"You needn't have done that" - "You shouldn't have done that" - ian-hill, May 24, 2011

Ian, how is "need" in the past? Wouldn't it be "needed"? - Sabor, May 24, 2011

an, with all due respect, you made this point on your own answer. I am trying to keep it simple for Deba so he does not feel overwhelmed by complicated grammatical constructs. - - NancyGrace, May 24, 2011

Well explained, Nancy:) - FELIZ77, May 24, 2011

Answer 2

Heidita has come close to "nailing it" here regarding a very subtle idiomatic construction. No, there is not a great difference in meaning, but, in context, there is a difference in usage:

Generally, we needn't do something, but we don't need a thing.

Using Yeser's example, "You needn't offer me a cigarette. Since I don't smoke, I don't need it."

As implied, "don't need" works in either context.

I have to differ a bit with Sabor and Yeser, though, as to the obsolescence of the "needn't" construction: Some of us still do use it, even though we're not 200 years old -- not quite yet.

I agree with you, I don't consider it totaly obsolute and do use it myself but never in certain examples as I stated - Yeser007, May 24, 2011

just a tiny sp. oversight -- not obsolute, but obsolete - NancyGrace, May 24, 2011

Answer 3

Hola debba:

Needn't do something: no hay necesidad de hacer algo.

You needn't clean this room, my maid just cleaned it. (no hace falta que lo limpie...)

You don't need to clean....sería en este caso lo mismo.

Pero puede cambiar sobre todo con tiempos en pasado :

He didn't need to come. No fue necesario que viniera y no vino.

He needn't have come. NO fue necesario que viniera PERO vino

You can say "He didn't need to come." even if it is a fact that he came. It is probably more common than saying "needn't" in American English. - lorenzo9, May 24, 2011

In fact, "You didn't need to do that." Usually means that you did in fact do it, but I wish you hadn't. - lorenzo9, May 24, 2011

Answer 4

There is absolutely no difference in meaning. Needn't is more old-fashioned and not heard much, if at all, in the US.

Well that's not entirely true. They are interchangeable in most cases but I would never say" I need not a new car". 200 years ago I may have said "I need not a new carriage" but we just don't speak that way today. If someone hands me a cigarette I would say "Thanks, but I don't need that, I don't smoke", I doubt anyone would say "Thanks but I need not a cigarette". Get the idea.

indeed, good one compi;) - 00494d19, May 24, 2011

Answer 5

Using Yesero's idea.

A) You don't need to offer me a cigarrette. Means - No es necesario.

B) You needn't offer me a cigarette = the same

But notice the infinitive to in A)

In England "needn't is used all the time.

My point Ian is this Ian. Would you say "I needn't a new car"? I'm not suggesting that it is improper grammar but here in the US I doubt that you would ever hear it. - Yeser007, May 24, 2011

No - one would not say that. One would say "I don't need a new car." - ian-hill, May 24, 2011

After "needn't" one would nearly always find another verb (similar to Modals) unless it is used as a short answer. "No you needn't" for example. - ian-hill, May 24, 2011

"I needn't buy a new car" - Sabor, May 24, 2011

Answer 6

Needn't doesn't always mean shouldn't have. In some contexts it means there is no necessity to, or you need not.

For example, 'Please come to my party but you needn't buy a gift'.

Granted, Wilbur, but then your sentence would fit into my first example. My intention was just to show Deba two common but different ways in which the words are used. - - NancyGrace, May 24, 2011

Answer 7

There is absolutely no difference in meaning. Needn't is more old-fashioned and not heard much, if at all, in the US.

No necesitas explicar.

You don't need to explain.