<p>someone brought it up few days ago,but i dont see any answers.
here:
Someone need not buy a car vs. Someone NEEDS not buy a car.</p>
<p>which one is right ? and why?</p>
<p>Someone (He, She) need not buy a car... I think. That's just an idiom. It's just the way we say it.</p>
<p>'Someone need not buy a car' is the correct one. Idiomatic usage.</p>
<p>In English, there are modal verbs such as "can," "will," and "must." These verbs have an identical singular and plural form and do not take an infinitive. For example, you say that "he can run" or "they can run" rather than "he can to run" or "they cans run." Of course, this is common sense. However, "need" is more tricky because it can be used as a modal verb, but it can also be used as a regular verb depending on the context. So you can say that "she needs to wash the dishes" or "she need wash the dishes." The latter usage is becoming increasingly scarce in the English language (generally, only the negative form, as in "she need not wash the dishes," is used). Due to the lack of an infinitive, it is clear that the modal form is being used. But, by ear, you can tell that a construction such as "he needs run" makes no sense. Also, note that the modal "need" has no past tense -- you can't say that "someone needed buy a car."</p>
<p>Begoner, thanks for the clarification. A friend also explained something similar, words like "can,must,might,may,etc".. modal verbs,ok thats what they're called. </p>
<p>wow,thanks!that's a new lesson for me =]</p>