Stems Compounded with Prepositions

127. These are of two readily distinguishable kinds

1. The preposition qualifies.
   

   ἐπι-μάρτυρος
   witness to (something)

   περι-κτίον-ες
   dwellers around

   ἀμφί-φαλο-ς
   with crest on both sides

   πρό-φρων
   with forward mind

   Forms of this kind are sometimes obtained directly from compound verbs: e.g. ἔξοχος from ἐξ-έχω, not from ἐξ and ὄχος.

2. The preposition governs, i.e. the compound is equivalent to a preposition governing a noun.
   

   ἐν-νύχ-ιο-ς
   in the night

   κατα-χθόν-ιο-ς
   underground

   ἀπο-θύμ-ιο-ς
   displeasing (lit. away frοm the mind), etc.

   also (but less commonly) without a secondary suffix.

   ἐγ-κέφαλο-ς
   brain (it. within the head)

   ἐπ-άρουρο-ς
   attached to the soil

The placing of the preposition before the gοverned stem is a departure from the general rule stated above. It may be held, however, that the preposition serves (in some of these compounds at least) as the limiting or qualifying member of the word. Compare νύχ-ιο-ς by night, ἐν-νύχ-ιο-ς within the night: it is evident that the ἐν limits the sense of νύχιος in essentially the same way as παν- in παν-νύχ-ιο-ς all the night. So κατα-χθόν-ιο-ς is nearly equivalent to χθόν-ιο-ς; the preposition merely makes it clear in what sense the suffix -ιο is to be understοοd—"belonging to the earth" by by being under it.