Koine Greek different from Ancient Greek
Name
The English-language name Koine is derived from the Koine Greek term ἡ κοινὴ διάλεκτος (hē koinḕ diálektos), meaning "the common dialect". The Greek word κοινή (koinḗ) itself means "common". The word is pronounced , , or  in US English and  in UK English. The pronunciation of the word koine itself gradually changed from [koinéː] (close to the Classical Attic pronunciation [koi̯.nɛ̌ː]) to [cyˈni] (close to the Modern Greek [ciˈni]). In Modern Greek, the language is referred to as Ελληνιστική Κοινή, "Hellenistic Koiné", in the sense of "Hellenistic supraregional language").Ancient scholars used the term koine in several different senses. Scholars such as Apollonius Dyscolus (second century AD) and Aelius Herodianus (second century AD) maintained the term koine to refer to the Proto-Greek language, while others used it to refer to any vernacular form of Greek speech which differed somewhat from the literary language.When Koine Greek became a language of literature by the first century BC, some people distinguished two forms: written as the literary post-classical form (which should not be confused with Atticism), and vernacular as the day-to-day vernacular. Others chose to refer to Koine as "the dialect of Alexandria" or "Alexandrian dialect" (ἡ Ἀλεξανδρέων διάλεκτος), or even the universal dialect of its time. Modern classicists have often used the former sense.Origins and history
Koine Greek arose as a common dialect within the armies of Alexander the Great. Under the leadership of Macedon, their newly formed common variety was spoken from the Ptolemaic Kingdom of Egypt to the Seleucid Empire of Mesopotamia. It replaced existing ancient Greek dialects with an everyday form that people anywhere could understand. Though elements of Koine Greek took shape in Classical Greece, the post-Classical period of Greek is defined as beginning with the death of Alexander the Great in 323 BC, when cultures under Greek sway in turn began to influence the language.
The passage into the next period, known as Medieval Greek, is sometimes dated from the foundation of Constantinople by Constantine the Great in 330 AD, but often only from the end of late antiquity. The post-Classical period of Greek thus refers to the creation and evolution of Koine Greek throughout the entire Hellenistic and Roman eras of history until the start of the Middle Ages.The linguistic roots of the Common Greek dialect had been unclear since ancient times. During the Hellenistic period, most scholars thought of Koine as the result of the mixture of the four main Ancient Greek dialects, "ἡ ἐκ τῶν τεττάρων συνεστῶσα" (the composition of the Four). This view was supported in the early twentieth century by Paul Kretschmer in his book Die Entstehung der Koine (1901), while Ulrich von Wilamowitz-Moellendorff and Antoine Meillet, based on the intense Ionic elements of the Koine – σσ instead of ττ and ρσ instead of ρρ (θάλασσα – θάλαττα, 'sea'; ἀρσενικός – ἀρρενικός, 'potent, virile') – considered Koine to be a simplified form of Ionic.The view accepted by most scholars today was given by the Greek linguist Georgios Hatzidakis, who showed that despite the "composition of the Four", the "stable nucleus" of Koine Greek is Attic. In other words, Koine Greek can be regarded as Attic with the admixture of elements especially from Ionic, but also from other dialects. The degree of importance of the non-Attic linguistic elements on Koine can vary depending on the region of the Hellenistic world.In that respect, the varieties of Koine spoken in the Ionian colonies of Anatolia (e.g. Pontus, cf. Pontic Greek) would have more intense Ionic characteristics than others and those of Laconia and Cyprus would preserve some Doric and Arcadocypriot characteristics, respectively. The literary Koine of the Hellenistic age resembles Attic in such a degree that it is often mentioned as Common Attic.Types
Biblical Koine
Biblical Koine refers to the varieties of Koine Greek used in Bible translations into Greek and related texts. Its main sources are:Differences in grammar
Phonology
During the period generally designated as Koine Greek, a great deal of phonological change occurred. At the start of the period, the pronunciation was virtually identical to Ancient Greek phonology, whereas in the end, it had much more in common with Modern Greek phonology.
The three most significant changes were the loss of vowel length distinction, the replacement of the pitch accent system by a stress accent system, and the monophthongization of several diphthongs:The ancient distinction between long and short vowels was gradually lost, and from the second century BC all vowels were isochronic (having equal length).
From the second century BC, the Ancient Greek pitch accent was replaced with a stress accent.
Psilosis: loss of rough breathing, /h/. Rough breathing had already been lost in the Ionic Greek varieties of Anatolia and the Aeolic Greek of Lesbos.
The diphthongs ᾱͅ, ῃ, ῳ /aːi eːi oːi/ were respectively simplified to the long vowels ᾱ, η, ω /aː eː oː/.
The diphthongs αι, ει, and οι became monophthongs. αι, which had already been pronounced as /ɛː/ by the Boeotians since the 4th century BC and written η (e.g. πῆς, χῆρε, μέμφομη), became in Koine, too, first a long vowel /ɛː/ and then, with the loss of distinctive vowel length and openness distinction /e/, merging with ε. The diphthong ει had already merged with ι in the 5th century BC in Argos, and by the 4th century BC in Corinth (e.g. ΛΕΓΙΣ), and it acquired this pronunciation also in Koine. The diphthong οι fronted to /y/, merging with υ. The diphthong υι came to be pronounced [yj], but eventually lost its final element and also merged with υ. The diphthong ου had been already raised to /u/ in the 6th century BC, and remains so in Modern Greek.
The diphthongs αυ and ευ came to be pronounced [av ev] (via [aβ eβ]), but are partly assimilated to [af ef] before the voiceless consonants θ, κ, ξ, π, σ, τ, φ, χ, and ψ.
Simple vowels mostly preserved their ancient pronunciations. η /e/ (classically pronounced /ɛː/) was raised and merged with ι. In the 10th century AD, υ/οι /y/ unrounded to merge with ι. These changes are known as iotacism.
The consonants also preserved their ancient pronunciations to a great extent, except β, γ, δ, φ, θ, χ and ζ. Β, Γ, Δ, which were originally pronounced /b ɡ d/, became the fricatives /v/ (via [β]), /ɣ/, /ð/, which they still are today, except when preceded by a nasal consonant (μ, ν); in that case, they retain their ancient pronunciations (e.g. γαμβρός > γαμπρός [ɣamˈbros], ἄνδρας > άντρας [ˈandras], ἄγγελος > άγγελος [ˈaŋɟelos]). The latter three (Φ, Θ, Χ), which were initially pronounced as aspirates (/pʰ tʰ kʰ/ respectively), developed into the fricatives /f/ (via [ɸ]), /θ/, and /x/. Finally ζ, which is still metrically categorised as a double consonant with ξ and ψ because it may have initially been pronounced as σδ [zd] or δσ [dz], later acquired its modern-day value of /z/.New Testament Greek phonology
The Koine Greek in the table represents a reconstruction of New Testament Koine Greek, deriving to some degree from the dialect spoken in Judea and Galilee during the first century and similar to the dialect spoken in Alexandria, Egypt. The realizations of certain phonemes differ from the more standard Attic dialect of Koine.Γ has spirantized, with palatal allophone before front-vowels and a plosive allophone after nasals, while β is beginning to develop a fricative articulation intervocalically.  φ, θ and χ still preserve their ancient aspirated plosive values, while the unaspirated stops π, τ, κ have perhaps begun to develop voiced allophones after nasals. Initial aspiration has also likely become an optional sound for many speakers of the popular variety. Monophthongization (including the initial stage in the fortition of the second element in the αυ/ευ diphthongs) and the loss of vowel-timing distinctions are carried through, but there is still a distinction between the four front vowels /e̞/, /e̝/, /i/, and /y/ (which is still rounded).