§ 7. A vowel beginning a word takes either the rough breathing, (῾), which is pronounced like h, or else, to show the absence of that, the smooth breathing, (᾿), which has no appreciable sound. Initial ρ and υ always take the rough breathing; and double ρ in the middle of a word takes the smooth breathing on the first, and the rough on the second.
§ 8. The vowels are short, (ε and ο,) long, (η and ω,) or doubtful, (α, ι, and υ,) which last, although naturally short, are sometimes lengthened by derivation.
§ 9. The diphthongs are as follows:--
[See Elpenor's The Greek Letters]
§ 10. In diphthongs the breathing and accent are written over the second vowel. A capital (initial) letter in other cases takes them before it.
§ 11. The punctuation marks are the comma, (,), the semicolon, (·), the period, (.), and the interrogation point, (;).
More Greek Learning Resources
The Greek Word Course
Reference address : https://www.ellopos.net/elpenor/lessons/strong1.asp?pg=2