Greek

Around 3,400 years of continuous written record — among the longest of any language. Mycenaean Greek in Linear B script dates to roughly 1400 BCE. Classical Greek of the 5th–4th centuries BCE produced the literary corpus that shaped Western literary tradition. Koine Greek of the Hellenistic and Roman periods became a Mediterranean lingua franca and the language of the New Testament. Byzantine Greek connected antiquity to medieval and modern times, and Modern Greek descends in unbroken line from these earlier stages.

Modern Greek descends from Ancient Greek through continuous evolution, but a Modern Greek speaker can't read Plato or the Iliad without study any more than an English speaker can read Beowulf. The grammar has simplified (one case lost, complex verb morphology streamlined), vocabulary has shifted, and pronunciation has changed enormously — the long vowels and pitch accent of Classical Greek are gone, replaced by stress accent and merged vowel sounds.

Greece had a major diglossic split through most of the 20th century between Katharevousa (a 'purified' formal variety closer to Classical Greek) and Demotic (the everyday spoken language). The split was politically charged and was resolved in 1976 when Demotic was officially adopted as the language of state, education, and most writing. Some Katharevousa vocabulary persists in formal and religious registers.

The Greek alphabet, in roughly its current form, dates back to the 8th century BCE — itself a modification of the Phoenician abjad. It's the ancestor of the Latin alphabet, the Cyrillic alphabet, the Coptic alphabet, and several others. Greek has 24 letters, with some letters that look identical to Latin but represent different sounds (Ρ is r, not p; Χ is the velar fricative ch, not x). Most learners read fluently within a couple of weeks.

The script takes a couple of weeks. Pronunciation is mostly regular. The grammar — three genders, four cases, complex verb conjugation across multiple aspects and moods — takes longer. Vocabulary contains substantial overlap with English through scientific and academic terms (philosophy, telephone, democracy), but everyday vocabulary has limited cognates. Most learners describe Greek as moderately difficult, comparable to Russian or Polish.