I don't understand how anyone could learn Greek with Duolingo...

I know there's a lot of people who claim that the best way to learn languages is like a child. Might work for them, doesn't work for me. I don't understand the Greek articles at all. I don't know when you use mia and when ena. Until I go and check out the Greek grammar, and see that mia is the feminine article and ena the masculine/neuter. Now, I KNOW there's some grammar in Duolingo, and it would be a really smart idea to click the question mark, especially when learning, but - most people don't. And they don't always offer it in Greek either :-D

I think it's a really stupid idea to not allow transliterating. I mean, the Greek letters are pretty straightforward and easily transliterated into Roman letters.  But no... they start whining about how to PRONOUNCE the words... That there are several different letters and diphthongs that are pronounced [i].  How are you going to learn to SPELL like that? And when they accept the use of ι υ οι ει for [i] (only one of those is i), I don't understand why they cry over the FACT that one doesn't learn to spell Greek words in Duolingo. "there are surprisingly many advanced Greek learners who don't know how to spell!"

I mean, have they never heard of ghoti? Or that people learn to spell French, too, totally inspite of how it sounds? Or that in Korean, Japanese and Arabic they actually teach transliterating as part of learning the letters?  And THAT PEOPLE STILL LEARN KOREAN, JAPANESE AND ARABIC AT DUOLINGO!!! Duolingo taught me how to read Arabic. 

Seriously, the people who are responsible for the Greek course at Duolingo! Greek is not difficult to transliterate! 

α - a
β - b
γ - g
δ - d
ε - e
ζ - z
η - e/ei
θ - th
ι - i
κ - k
λ - l
μ - m
ν - n
ξ - x
ο - o
π - p
ρ - r
σ - s
τ - t
υ - u/y
φ - f/ph
χ - ch
ψ - ps
ω - o

And then just give people trick alternatives of words deliberately written wrong, and don't accept anything but the correct alternative. That's how you teach people when you write η and when ε. When to use omega and when omicron. Which letters are used to form the i-sound in this word. Not by accepting ι as typo for υ, "because it sounds the same". Idiots.

Anyway, about transliterating - you do it by exchanging a letter to a letter (or a specific letter combination) Like in Russian, С - s,Ш - sh, Ц - c,Ч - ch,З - z,Ж - zh, and Щ - shc.
This works like this: I sound the name of the letter when I write it. 
You know, cee, a, tee - cat. 
Gamma - alpha - tau - alpha - γατα - gata. 
ka - o - sha - ka - a - кошка koshka.
I mean... if I know democracy in Greek is written demokratia, it might make it harder for me to remember it's pronounced "ðimokratía", but easier to know it's spelled δημοκρατία and not διμοκρατία. That Duolingo accepts "διμοκρατία" as a correct answer - with a typo - but not demokratia, is just stupid.

I am not going to get myself a Greek keyboard. I got myself a Russian one, and then I forgot to change it back to Swedish, and closed the computer, and everything was in Russian when I opened it again... I can tell you it took some time to change it back to Swedish. And it wasn't easy. I almost cried before I got it back. I do not want to go through that with the Greek keyboard as well.

So - I'm probably not going to do much Greek in Duolingo. 

So, someone said "how are you going to learn to read and write Greek without a keyboard?"
The same way I LEARNED TO READ AND WRITE EVERY OTHER WRITING SYSTEM, you idiot! We didn't get a keyboard at first class when we taught to read and write my mothertongue, and it wouldn't have helped any with the reading. NO-ONE USES THE KEYBOARD TO READ. 

Also, when I'm learning things like "this is a woman, this is a man, I am a girl, you are a boy, cat ate fish" and so on - I'm still a beginner and will probably be for a VERY LONG TIME - I think my priority should not be to learn to touch-type yet another keyboard layout. Because that's how it's going to be. You see, the Greek keyboard layout is different from the Latin one, because they have created theirs according to the how their language works. 

Our keyboard is abcdefghijklmnopqrstuvwxyz.

Theirs is αβψδεφγηιξκλμνοπ;ρστθωςχυζ

You see, they don't have a c, h, j, q, u, v or w. But they do have ps, two es, th, two os and ch. Now, I think they should have put χ as h and ξ as x, but I suppose they have more use for μ and need it to be one of the most used keys in the middle... Anyway, it's different, and requires learning. (Of course it's easier than the Russian keyboard, but, alas, I have already started learning to touch type Russian, so...)

But on the other hand, I have a keyboard I can use, and then just copy and paste... though I don't like it. I'd much rather just write on Duolingo. And probably they'll remove the cut and paste option, too :-D

Anyway, I was using the word bank, but they have this vocabulary test, which doesn't give you options. You have to write it as it is. And they don't give you a Greek keyboard. So cut and paste it is. And when I was complaining about this, someone said they are pretty certain of that there's a button I can click. Yeah... I posted a screen shot and asked them to show me where the button is, because it's not there. Really easy for people to learn Greek.

And then we have the funny little fact that some countries that used to use Cyrillics to write their language, have changed to Latin alphabet - AND MANAGED TO MAKE THE CHANGE WITHOUT MUCH PROBLEMS.  

It doesn't make things better that I think the woman reading the words is hard to understand. Her Greek isn't very clear, and it's hard to hear what she says. 

So, no, Duolingo Greek is not something I would recommend.

How to practice speaking skills alone?

Now, I am talking about English. It's quite possible and not even difficult to get good at speaking English without ever talking with anyone. It's harder when it comes to other languages, but the most common languages are almost as easy as English.
When it comes to other languages - learn IPA, and you will get close enough. It's not perfect, of course, but it's good enough to get you understood and able to correct your mistakes.

1) Speak. Say everything you are learning. If you go to Duolingo, read all the sentences and words out loud. You don't need to put in any air in your speaking, so that you can do it in a public library or a bus or anywhere without getting attention. Just try it. Read out loud this sentence without any sound - you HEAR your voice reading this. You feel your mouth, tongue, lips making the movements.
Learn the pronunciation rules, and IPA, and get an estimation of how you think the words should be pronounced, and then compare your estimation to reality, and correct your pronunciation accordingly.
"Repeat after ---". Parrot the words.

1) Read texts aloud. Record your speech. Listen to it and compare to a native speaker. Try to get it as close as possible.
If you are having difficulties getting some specific words to sound right, there's plenty of sites where people pronounce specific words. (Like Forvo, for example.)
Again, in English you probably can find every word pronounced by a native speaker somewhere online, in Navajo, not so likely.
Audiobooks are excellent for this purpose, and it doesn't matter if the books are modern or in public domain. The anciency of the language is irrelevant.
You can also read along with the native speaker. You will be able to spot the differences better this way. :-D Make notes on what you usually miss and practice that.

2) Speak about things in your chosen language. It doesn't much matter if you get it right or not. Speak clearly, do your best, but don't focus on if you get it right. You don't know. You can't know. But speaking a lot makes you better at speaking. Yes, it is highly possibly you develop some bad habits or learn something wrong, but it will be quickly corrected, if you ever get to use the language in real situation. If you don't, then nobody cares - or should care. Also, that's why you would be doing the first thing I suggested, to get it right. THERE it is important to get it as right as you possibly can.

3) Sing.

4) Practice tongue twisters.

Practice what is most difficult to you, what you have most problems with, and pronounce it loud and clear (at least when you are alone). Pronounce the words as if you were talking to a person who can't hear very well, or if you were trying to teach someone how to pronounce it correctly. It's really easy to mumble and try to be quick, so as people can smooth over the possible errors and problems, but what will you learn of that? You will learn to mumble, you will learn to pronounce the words wrong and YOU WILL LEARN THAT YOU CAN'T LEARN TO SPEAK WELL.

"C2 is impossible to be reached by self-learning."

Oh... challenge accepted!

I would say most of my languages are at this point "self-learned", except Finnish (my mothertongue), English (9 years in school and then life) and Swedish (6 years in school, then living in Sweden since 1995).
I have studied German in school for 2 years, and French 1, and I have 2 lessons of Arabic, but German was 1985, French 1997 and Arabic also in the 80s :-D I haven't used any of this with another living person.

"C2 is quite hard to reach in general, even native speakers are not on this level (they're usually somewhere at B2/C1)."
Seriously? I have been living in Sweden for 24 years now, and my Finnish has deteriorated a lot, but my Finnish was definitely C2 when I lived there.

The CEFR test says my English is ""≥C1" means that you are at the C1 level, or “maybe even C2”, but the test does not assess the C2 level."
Now, it doesn't assess my spoken language, but I'm fully confident in it.
Anyway, if I can get any of the other languages (not Finnish or Swedish) to the same level as my English - which is my goal - through internet and self-studies only, then I have proven the statement in the subject line false.
And I am absolutely certain of that this is possible, at least in the most common languages with plenty of access to all kinds of materials online, like French, Spanish, Portuguese, Italian, Chinese, Korean, Japanese...