The English auxiliary need is also an NPI. Compare the following examples:

i

 You need not hurry.
*You need hurry.
ii

 You need only ask.
*You need ask.

The main verb to need, however, is not polarity sensitive, as is shown by the following examples:

iii
 They all need to hurry.
iv
 You need to ask him.

See also section 1.5.4.

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