How to say "thank you" in Classical Greek?

Here is the part of the dedication that I referred to:

Οὐ λανθάνει δὲ σέ, ὥσπερ οὐδ’ ἄλλο τι τῶν κατὰ παιδείαν, ὥς τινες ἀποπεπτωκότες τῆς ἀρχαίας φωνῆς, καὶ ἐπὶ τὴν ἀμαθίαν καταφεύγοντες πορίζουσι μάρτυράς τινας τοῦ προειρῆσθαι ὑπὸ τῶν ἀρχαίων τάσδε τὰς φωνάς· ἡμεῖς δὲ οὐ πρὸς τὰ διημαρτημένα ἀφορῶμεν, ἀλλὰ πρὸς τὰ δοκιμώτατα τῶν ἀρχαίων.

Very roughly:

“It does not escape your notice, like everything else related to education, that some who have fallen away from the ancient language and fled to ignorance furnish witnesses [i.e., examples] that such sounds/words have been spoken/used previously/in the past [προειρῆσθαι] by the ancients. We look not to the mistaken, but rather to the most approved/exemplary [understand maybe ‘usages’] of the ancients. After all, if anyone should offer them the choice as to whether they wanted to speak in the ancient manner and correctly or with new-fangled innovations and carelessly, they would accept/choose above all to belong to the better party/class [of speakers and writers of Greek], coming into agreement with us. For no one is so wretched as to prefer ugliness to beauty. Take care.”

Joel, could you post the remainder of the introduction for comparison (not the beginning, just the end, after what you posted above)?

Phrynichus is like people who insist that you can’t use “decimate” in English to mean “destroy a large part of” because it meant “kill every tenth man” in Latin.

http://blog.oxforddictionaries.com/2012/09/does-decimate-mean-destroy-one-tenth/

An even better analogy: Phrynichus is like people who claim that singular “they” is wrong. When confronted with examples of singular “they” from 500 or more years of the best English writing, starting Chaucer and including Shakespeare, the King James Bible, Jane Austen, Henry James, etc., respond by insising “But that doesn’t make it right.”

http://languagelog.ldc.upenn.edu/nll/?p=24504

Same with split infinitives.

The section that Hylander has translated:

Οὐ λανθάνει δὲ σέ, ὥσπερ οὐδ’ ἄλλο τι τῶν κατὰ παιδείαν, ὥς τινες ἀποπεπτωκότες τῆς ἀρχαίας φωνῆς, καὶ ἐπὶ τὴν ἀμαθίαν καταφεύγοντες πορίζουσι μάρτυράς τινας τοῦ προειρῆσθαι ὑπὸ τῶν ἀρχαίων τάσδε τὰς φωνάς· ἡμεῖς δὲ οὐ πρὸς τὰ διημαρτημένα ἀφορῶμεν, ἀλλὰ πρὸς τὰ δοκιμώτατα τῶν ἀρχαίων. καὶ γὰρ αὐτοῖς εἴ τις αἵρεσιν προθείη, ποτέρως ὰν ἐθέλοιεν διαλέγεσθαι ἀρχαίως καὶ ἀκριβῶς ἢ νεοχμῶς καὶ ἀμελῶς, δέξαιντ’ ἂν ἀντὶ παντὸς ἡμῖν σύμψηφοι γενόμενοι τῆς ἀμείνονος γενέσθαι μοίρας· οὐ γάρ τις οὕτως ἄθλιος, ὡς τὸ αἰσχρὸν τοῦ καλοῦ προτιθέναι. ἔρρωσο.

Thank you especially for καὶ γὰρ αὐτοῖς εἴ τις αἵρεσιν…γενέσθαι μοίρας. I stumbled on that pretty badly, though now it appears obvious.

EDIT: φενόμενοι → γενόμενοι, caught by Hylander.

φενόμενοι should be γενόμενοι?