23.4 Declining most 3rd Declension nouns whose stem ends in –ρ is fairly straightforward. Greek often avoids the combination –ρσ-, usually by dropping the –ς from the NOMINATIVE SINGULAR (μάρτυς μάρτυρος ὁ, ἡ is a break from this tendency). In the DATIVE PLURAL, the –σι ending is always intact. What happens when the –ρ– encounters the –σι can vary. Many nouns simply allow the full –ρσι– combination. For example, the dative plural of ῥήτωρ ῥήτορος ὁ, orator is ῥήτορσι(ν) (S 259, G 132). There are, however, exceptions to this pattern:
μάρτυς μάρτυρος ὁ, ἡ drops the ρ for most Greek authors: μάρτυσι(ν)
χείρ χειρός ἡ shortens its stem: χερσί(ν)
Note the inflections of the following common nouns, each with their own slight peculiarities:
(cf. G 142.4)
(cf. G 142.10)
(cf. G 142.8)
