213. In early Greek ὅς, ἥ, ὅ was demonstrative, like ὁ, ἡ, τό (205). In Attic it retains this force in a few phrases (560), but is commonly relative, meaning who, which, that. The forms are:
215. To the demonstratives in 211, 212 correspond the relatives
|οἷος,||οἵᾱ,||οἷον||of which kind, (such) as
[Latin qualis: of quality]
|ὅσος,||ὅση,||ὅσον||of which size or number, (as great or many) as
[Latin quantus or quot: of quantity]
|ἡλίκος,||ἡλίκη,||ἡλίκον||of which age or value|
216. The enclitic particle -περ added to a relative pronoun (or adverb; see 236) makes more distinct the reference to the antecedent, which is thereby emphasized.
ὅπερ which very thing, the very thing which
ὥσπερ just as
θέλω ἅπερ σύ
I wish the very things that you do.
(Eur. Ipheginia in Tauris, 991)