надо и нужно

[watsong]

There exists the Russian words: 'надо' and 'нужно'.

These two words seem to have exactly the same meaning. Is this true? What is the difference in usage of these two words?

e.g. Мне нужно такси.
Мне надо такси.

[ddvossler]

надо means I must, I should, I need to - with a moral like obligation implied:
"I need to call my mom." (guilt guilt guilt)
"I should give to charity." (guilt guilt guilt)
(должен is a ought to/should/must also with a hint of moral obligation but is used with nominative nouns - unlike надо and нужно which are used with dative nouns)

нухно is a more straight forward need without moral obligation implied:
"I need a pencil for this task."
"I should buy a cell phone for this job."

[watsong]

I think that I understand. Thank you.

Мне надо такси (A taxi is necessary to me in order to get where I am going.)
Мне нужно такси (I need a taxi but could also take an alternative, like a bus.)

[baggieonline]

I think there is a big difference in the negatives. Unless I am mistaken:

ne nado + infinitive = shouldn't do something.
ne nuzhno + infinitive = it's not necessary to do something

Apologies for not writing in Russian - posting this from my PSP.

[roxanasharie]

As a native speaker I can say that there`s no real difference in надо and нужно. Although you won`t find надо much in written Russian, because it`s a very colloquial form of "I need" and not used even in polite conversations. The usage of these words is also a little different. Usually we don`t put nouns after "надо" as in the examples above: "мне надо такси". It sounds much more correct if you use it with the verbs: "Мне надо идти"-I have to go. "Нужно" is also used exclusively with verbs, but you can use it with nouns IF you modify this word according to genders:

Мне нужен телефон - I need a phone
Мне нужна ручка - I need a pen
Мне нужны деньги - I need money

You probably came across "надо" a lot more often on RussianPod. But that`s just for the total beginner lessons, because "надо" is not modified according to genders and is easier to pronounce. Although... personally I wouldn`t recommend using too much, it`s rather slangy. Like "I gotta go" maybe, though it`s hard for me to catch the feeling of the English "gotta" "havta"

Должен - is a totally different story. It just mean "must, have to" and implies obligation.
And again, "надо" and "нужно" have the same meaning - "need, should", and only differ in usage and level of speech.

[watsong]

I am very pleased to hear the real usage of these words.

This thread demonstrates, that it is important to know whether someone is a native Russian speaker before fully believing their statements on Russian language.

Thus, for me, 'roxanasharie' is now an authoritative figure on Russian language learning.

Thank you very much, roxanasharie!