In subordinate clauses μή or οὐ is used.
a. Final clauses have μή, as φίλος ἐβούλετο εἶναι τοῖς μέγιστα δυναμένοις, ἵνα ἀδικῶν μὴ διδοίη δίκην
he wished to be on friendly terms with men in power in order that he might not pay the penalty for his wrong-doing X. A. 2.6.21, ἔδει τὰ ἐνέχυρα τότε λαβεῖν, ὡς μηδ᾽ εἰ ἐβούλετο ἐδύνατο ἐξαπατᾶν quoted in 2185 c.
b. Object clauses with ὅπως after verbs of effort have μή, as φρόντιζ᾽ ὅπως μηδὲν ἀνάξιον τῆς τῑμῆς ταύτης πρᾱ́ξεις
see to it that you do nothing unworthy of this honour I. 2.37, ἐπεμέλετο ὅπως μήτε ἄσῑτοι μήτε ἄποτοί ποτε ἔσοιντο
he took care that they should never be without food or drink X. C. 8.1.43.
c. Conditional clauses regularly have μή. Thus, εἰ μὴ ῡ̔μεῖς ἤλθετε, ἐπορευόμεθα ἂν ἐπὶ βασιλέᾱ
if you had not come, we should be marching against the king X. A. 2.1.4, οὐκ ἀπελείπετο αὐτοῦ, εἰ μή τι ἀναγκαῖον εἴη
he never left him unless there was some necessity for it X. M. 4.2.40. So in concessive clauses (2369). On οὐ adherescent in conditional clauses see 2696.
d. Relative Clauses, if conditional, have οὐ with a definite antecedent, μή with an indefinite antecedent (2505). μή is thus used when the case in question is typical of a class (μή ‘generic’). Thus, προσημαίνουσιν ἅ τε χρὴ ποιεῖν καὶ ἃ οὐ χρή
they signify beforehand what one must do and what not X. C. 1.6.46, ἃ μὴ οἶδα οὐδὲ οἴομαι εἰδέναι what I do not know, I do not even think I know P. A. 21d.
N. 1.—Homer has ὃς (ὅσος) οὐ with the indicative (μή B 301).
N. 2.—οὐ is regular in relative clauses when an opposition is expressed (T. 1.11. 2), and when a negative clause precedes; as οὐκ ἔστιν ὅστις (ὅπως) οὐ οὐδεὶς ὅστις οὐ, etc. (X. C. 1.4.25, X. A. 2.4.3).
e. The expression τοιοῦτος, ὅς (ὅστις, etc.), when preceded by a negative, takes οὐ; as ταμιεῖον μηδενὶ εἶναι μηδὲν τοιοῦτον, εἰς ὃ οὐ πᾶς ὁ βουλόμενος εἴσεισι it is necessary that no one shall have (such) a storehouse that anybody who pleases may not enter it P. R. 416d. But even when no negative precedes, we have οὐ, when the relative clause makes an assertion or defines attributively; as συγγραφεὺς τῶν λόγων . . . τοιοῦτος, οἷος οὐδεὶς ἄλλος γέγονε
such a writer of speeches as no one had been I. 15.35. When the antecedent is general or is thought of in respect of its character we have μή; as βουληθεὶς τοιοῦτον μνημεῖον καταλιπεῖν, ὃ μὴ τῆς ἀνθρωπίνης φύσεώς ἐστιν
wishing to leave behind him such a memorial as would surpass human nature I. 4.89; cp. 2705 g.
f. Relative clauses of purpose take μή, as θαλάσσιον ἐκρῑ́ψατ᾽, ἔνθα μήποτ᾽ εἰσόψεσθ᾽ ἔτι
cast me out into the sea where ye may never see me more S. O. T. 1411, κρύψᾱσ᾽ ἑαυτήν, ἔνθα μή τις εἰσίδοι
hiding herself where no one might see her S. Tr. 903.
g. Clauses with a relative pronoun referring to an antecedent thought of in respect of its character (of such a sort) take μή. The use of μή characteristic comes from the generic meaning of μή, i.e. the antecedent is not regarded simply as a person who does something but as a person of such a nature as, one who typifies a class. In such cases ὃς μή may refer to a definite person or thing. So especially in relative clauses of cause and result, which ordinarily take οὐ. Thus, ταλαίπωρος ἄρα τις σύ γε ἄνθρωπος εἶ . . ., ᾧ μήτε θεοὶ πατρῷοί εἰσι μήτε ἱερά
a wretched being art thou then, who hast neither ancestral gods nor shrines P. Eu. 302b, ψηφίσασθε τοιαῦτα ἐξ ὧν μηδέποτε ῡ̔μῖν μεταμελήσει
pass such a vote that you will never repent of it And. 3.41, τοιαῦτα λέγειν . . ., οἷς μηδεὶς ἂν νεμεσήσαι
to use language at which no one could feel just resentment D. 21.161, ὁ . . . μηδὲν ἂν ὀμόσᾱς the man who would not take an oath 54. 40. Sophocles is especially fond of the generic μή.
h. Consecutive clauses (and consecutive relative clauses) with ὤστε take οὐ with the indicative and optative. Thus, (Λακεδαιμόνιοι) εἰς τοῦτ᾽ ἀπληστίᾱς ἦλθον ὥστ᾽ οὐκ ἐξήρκεσεν αὐτοῖς ἔχειν τὴν κατὰ γῆν ἀρχήν the Lacedaemonians became so insatiate in their desires that they were not satisfied with their empire on the land I. 12.103, ὥστ᾽ οὐκ ἂν αὐτὸν γνωρίσαιμ᾽ ἂν εἰσιδών
so that I should not recognize him, if I were to see him E. Or. 379. On τοιοῦτος ὃς οὐ see 2705 e.
i. Oaths and protestations in the indicative with μή express a solemn denial or refusal, or repudiate a charge. Thus, ἴστω νῦν Ζεὺς . . . μὴ μὲν τοῖς ἵπποισιν ἀνὴρ ἐποιχήσεται ἄλλος let Zeus now know (i.e. I swear by Zeus) that no other man shall mount these horses K 329, μὰ τὴν Ἀφροδῑ́την . . . μὴ ᾽γώ σ᾽ ἀφήσω by Aphrodite, far be it from me that I should release you Ar. Eccl. 999. Cp. 2716.