Several prefixes occur only in composition:
1. ἀ(ν)- (ἀν- before a vowel, ἀ- before a consonant; alpha privative) with a negative force like Lat. in-, Eng. un- (or -less): ἀν-άξιος unworthy (= οὐκ ἄξιος), ἀν-όμοιος unlike, ἀν-ώδυνος anodyne (ὀδύνη pain, cp. 887), ἄ-νους silly, ἄ-τῑμος unhonoured, ἄ-θεος godless, γάμος ἄγαμος marriage that is no marriage. ἀ- is also found before words once beginning with digamma or sigma: ἀ-ηδής unpleasant (ϝηδύς), ἀ-όρᾱτος unseen (ϝοράω), ἄ-οπλος without shields (σοπλον), and, by contraction with the following vowel, ᾱ̓́κων (ἀ-ϝέκων unwilling). But ἀν- often appears: ἀν-έλπιστος (and ἄ-ελπτος) unhoped for (ϝελπίς), ἄν-οπλος without shield.
a. ἀ-, ἀν- (for ṇ, 35 b) represent weak forms of I. E. ne ‘not.’
2. ἡμι- half (Lat. sēmi-): ἡμι-κύκλιος semi-circular (κύκλος), ἡμι-όλιος half as much again (ὅλος whole), ἡμι-θνής half-dead.
3. δυσ- (opposed to εὖ well) ill, un-, mis-, denoting something difficult, bad, or unfortunate, as δυσ-τυχής unfortunate, δυσ-χερής hard to manage, δυσδαίμων of ill fortune (contrast εὐ-τυχής, εὐ-χερής, εὐ-δαίμων), δυσ-άρεστος ill-pleased, Δύσ-παρις ill-starred Paris.
4. ἀ- (or ἁ-) copulative denotes union, likeness (cp. Lat. con-); ἀ-κόλουθος attendant, agreeing with (κέλευθος path: i.e. going on the same road), ἀ-τάλαντος of the same weight, ἅ-πᾱς all together. A variation of ἀ-copulative is ἀ- intensive: ἀ-τενής stretched (τείνω stretch), ἄ-πεδος level (πέδον ground).
a. ἀ- copulative stands for σα- (from σṃ 20, 35 c), and is connected with ἅμα, ὁμοῦ, and ὁμο- together.
5. νη- (poetic) with the force of a negative (cp. Lat. nē): νή-ποινος unavenged (ποινή punishment), νη-πενθής freeing from pain and sorrow (πένθος). In some cases νη- may be derived from ν (not) and the η of the second part, as ν-ῆστις not eating (poetic ἔδ-ω, cp. 887).
6. ἀρι-, ἐρι- (poetic) with intensive force (cp. ἄρι-στος best), ἀρι-πρεπής very distinguished (πρέπω), ἐρί-τῑμος precious.
7. ἀγα- (poetic) intensive (cp. ἄγαν very): ἀγά-στονος loud wailing (στένω groan).
8. ζα-, δα- (poetic) intensive (for δι̯α = δια- very, 116): ζα-μενής very courageous (μένος courage), δά-σκιος thick-shaded (σκιᾱ́).