It's helpful to have some Latin under your belt before you tackle ancient Greek. If your ultimate aim is to engage with ancient Greek literature at an advanced level, Latin is really essential because (1) classical Latin literature to a large extent illuminates Greek literature--almost every classical Latin author writes with a Greek literature in mind (this is less true of New Testament Greek, which can be learned independently of Latin)--and (2) much scholarship on ancient Greek, particularly that written before about 1850-1875, much of which is still relevant, is written in Latin (prefaces to many scholarly editions of ancient Greek authors, even those written though the 1970s, have traditionally written in Latin--but you also need to be able to read French, Italian and, above all, German, too). I would suggest having the equivalent of a year or so of Latin before you really throw yourself into Greek, but you can start learning some Greek even earlier. Also, Latin and Greek have a similar structure, but Latin is easier.
Mastonarde is very rigorous and thorough, but many students, especially those studying on their own, seem to dislike his approach. No real need to buy anything else until you've worked your way through Mastronarde, though. Maybe others have different recommendations; I learned with Crosby and Schaeffer many years ago, long before Mastornarde was published, and I wasn't self-taught.
Modern Greek is quite different from ancient Greek. You probably won't be able to converse with your friend if you learn ancient Greek, even if you use the modern Greek pronunciation for ancient Greek. (I wouldn't recommend that--too many ancient Greek vowels and diphthongs have merged--but you don't really need to pronounce ancient Greek precisely like an ancient Greek--after all, there are no native speakers--an approximately accurate pronunciation will do.) The two phases of the language aren't as far apart as many think, and anyone who has some ancient Greek can make out much modern Greek, but there are big differences.
Achieving fluency in reading is a long and arduous process. There are several dialects of ancient Greek, and my experience is that you really never achieve fluency in all of ancient Greek--you may achieve fluency in a specific author or a specific genre, but when you turn to something else, it takes a while before you are reading with something approaching fluency. You'll never outgrow your need for a dictionary and a grammar, though. Never forget that you're reading texts written 2,000+ year ago, in a very different society, and preserved by a very imperfect process of copying and recopying for most of that period. Ancient Greek is hard.
I'm sure there will be some who don't agree with what I've written. Let's keep an open mind, let them air their views, and see what they have to say.
Last edited by Qimmik
on Fri May 16, 2014 2:21 am, edited 1 time in total.