To the perennial question of whether or not learning modern Greek first is better, this native Greek speaker and teacher perfectly summarizes my own arguments on the subject:
This is a seemingly very political issue for many. So many you tube video comment sections are packed with modern Greeks raging on the subject.
All too true. What I liked about her assessment was that she attempted to ground her comments in actual historical-linguistic facts.
Mine too! There is one expression she mentioned “δόξα τω θεώ” (δόξα τῷ θεῷ) which I think she meant to use as example of a carry over. Even though θεός is in the dative, it is still understood by all native modern Greek speakers. On the other hand, “οὐδ’ ἀπὸ δόξης” (Iliad 10.324) probably wouldn’t be understood, even though the individual words are exactly the same in modern Greek.
How many Greeks do you know who have a good grasp of the ancient language? The Greeks I know say they had to study it in school, hated it, and have now completely forgotten it. Something along the lines of “my high-school French.”
She didn’t necessarily give me the impression of someone who was speaking from a lot of personal experience on this. I didn’t hear any anecdotes about how much time it took her to learn ancient Greek, etc. (Though I didn’t listen all the way to the end.) So for me, it hasn’t answered the question of just how much help modern Greek is for getting to particular level of fluency.
I have also gotten more wary about overgeneralizing from the comments of any individual Greek. Shakespearean English doesn’t take much preparation to pick up. But I’m sure that there are plenty of nearly illiterate native English-speakers that people could use to prove me wrong, because it’s all Greek to them.
When I was an undergrad, we would fairly regularly get modern Greek speakers in “easy” Greek courses such as NT or Xenophon. Those who had not had ancient Greek or who were like the students you mention above quickly dropped out. Those who had studied previously and had paid attention did reasonably well, but not necessarily better than those of us who started Greek in their first semester of college.
I had this discussion with Maria Pantelia (now at UC Irvine) who essentially agreed. If you already have modern Greek, it can be an initial leg up getting started, but after a while it levels out, so that at the advanced levels native Greek speakers are not going to be necessarily somehow better than a native English speaker in terms of competence.