to need to, to have to (in negation or with the adverb nur (“just, only”))
Usage notes
Traditionally, brauchen has been a weak verb in standard German with a regular past subjunctive brauchte. However, the irregular form bräuchte has since found its way from the dialects into the standard. It is already the only common form in spoken German,[1] and is gradually becoming dominant in writing as well (although some grammars may still discourage this usage).
If the verb is used with another verb in the perfect or pluperfect tense, the infinitive replaces the past participle (ich hätte es nicht zu machen brauchen).
In colloquial German, the verb may be even further assimilated to modal verbs by taking a bare infinitive instead of a zu infinitive (du brauchst nicht schreien instead of standard du brauchst nicht zu schreien) and sometimes by taking an endingless third-person singular present (er brauch, instead of er braucht). Both of these are properties of modal verbs, cf. er soll gehen, er muss bleiben.
In archaic usage, in the sense of "to be in need of" or "to require", brauchen could take a genitive object instead of an accusative one.