The Greek Alphabet (Α, Β, Γ)

The Greek Alphabet, is the ancient Greek alphabet, that dates back to the 8th century BC, and it is the ancestor of the Latin Alphabet, the Cyrillic Alphabet and many others.
It consists of 24 letters, 17 consonants and 7 vowels.
When I was little, the teachers used to teach us the vowels with this little poem (in Greek it rhymes):

"Τα φωνήεντα είναι εφτά
  και φωνάζουν δυνατά:
  άλφα, έψιλον, ήτα, γιώτα, όμικρον, ύψιλον, ωμέγα!"


The vowels are seven
and they shout loudly:
...and we all used to say out loud the names of the vowels!

So this is the Modern Greek Alphabet, with the seven vowels being blue:
Remember that the Greek letters, have only ONE way to pronounce each. What you see is what you read. Except of course the several vowel or consonant combinations, that we will talk about later.

(This video is a bit of a YouTube vintage, but you've made it a classic! Thank you so much btw!)

Α, α
Β, β
Γ, γ
Δ, δ
Ε, ε
Ζ, ζ
Η, η
Θ, θ
Ι, ι
Κ, κ
Λ, λ
Μ, μ
Ν, ν
Ξ, ξ
Ο, ο
Π, π
Ρ, ρ
Σ, σ
Τ, τ
Υ, υ
Φ, φ
Χ, χ
Ψ, ψ
Ω, ω

The good news is that these seven vowels, do not express seven different sounds, but actually only four. But what do I mean?
The vowels

1. Άλφα is for the α sound, the simple sound we make when we say aaahhh, when we are surprised! Never pronounce the Greek Α as the English a in "make", it does not have an /ˈeɪ/ sound.
2. Έψιλον is for the /ε/ sound, something like in the English word "bed", but more clear and sharp. Just keep that in mind for every Greek letter. Clear and sharp. Attention: There is a vowel combination (αι) that represents the exact same sound. We will talk about it later.
3. H, I and Υ, all represent the same sound! A long time ago, of course they didn't but now they do. The sound ι, as y in "easy". Never pronounce any of these vowels as y in "fly". Attention: There are also three vowel combinations (ει, οι, υι) that produce the exact same sound, and will talk about them later.
4. O and Ω, both represent the sound / ɔ/, you have to round your lips to make the right sound, something like o in "more".

Easy, right? But remember, just because they sound the same, we are not allowed to use any letter we like in written speech. There are strict orthographic (spelling) rules, tha we should always keep in mind, if we want to have a complete education.  These rules, originate from the ancient language and we absolutely have to respect them.
In Greece, spelling is very important and quite difficult. Many well educated people, make common spelling mistakes, because they don't know which ι or ε, or ο, το use, especially because the sounds are all the same and give no clue. To master the Greek orthography, you have to study and read a lot. 

Now, watch my YouTube video about the pronunciation of each letter, so that you can listen to everything you just read and of course the sounds of the consonants.
I'm sure you will notice that you already know many of these letters, but you didn't pronounce them right.