The Greek language has contributed to the English lexicon in five main ways: Of these, the neologisms are by far the most numerous.
Since the living Greek and English languages were not in direct contact until modern times, borrowings were necessarily indirect, coming either through Latin (through texts or through French and other vernaculars), or from Ancient Greek texts, not the living spoken language.
A large group of early borrowings, again transmitted first through Latin, then through various vernaculars, comes from Christian vocabulary: In some cases, the orthography of these words was later changed to reflect the Greek—and Latin—spelling: e.g., quire was respelled choir in the 17th century.
In contrast, the Romance languages generally used the Latin words ecclēsia (French église; Italian chiesa; Spanish iglesia) or basilica (Romanian biserica), both borrowed from Greek.
Some words were borrowed in essentially their original meaning, often transmitted through Classical Latin: topic, type, physics, iambic, eta, necromancy, cosmopolite.
A few result from scribal errors: encyclopedia < ἐγκύκλιος παιδεία 'the circle of learning' (not a compound in Greek); acne < ἀκνή (erroneous) < ἀκμή 'high point, acme'.
Neologisms using these elements are coined in all the European languages, and spread to the others freely—including to Modern Greek, where they are considered to be reborrowings.
Examples include: encyclopaedia / encyclopædia / encyclopedia; haemoglobin / hæmoglobin / hemoglobin; and oedema / œdema / edema.
Since the 19th century, a few learned words have been introduced using a direct transliteration of Ancient Greek, including the Greek endings, rather than the traditional Latin-based spelling: nous (νοῦς), koine (κοινή), hoi polloi (οἱ πολλοί), kudos (κύδος), moron (μωρόν), kubernetes (κυβερνήτης).
For this reason, the Ancient Greek digraph ει is rendered differently in different words—as i, following the standard Latin form: idol < εἴδωλον; or as ei, transliterating the Greek directly: eidetic (< εἰδητικός), deixis, seismic.
Most learned borrowings and coinages follow the Latin system, but there are some irregularities: Some words whose spelling in French and Middle English did not reflect their Greco-Latin origins were refashioned with etymological spellings in the 16th and 17th centuries: caracter became character and quire became choir.
In some cases, a word's spelling clearly shows its Greek origin: There are some exceptions to this pattern: In clusters such as ps-, pn-, and gn- which are not allowed in English phonotactics, the usual English pronunciation drops the first consonant (e.g., psychology) at the start of a word; compare gnostic [nɒstɪk] and agnostic [ægnɒstɪk]; there are a few exceptions, such as tmesis [t(ə)miːsɪs].
In the case of Greek endings, plurals sometimes follow the Greek rules: phenomenon, phenomena; tetrahedron, tetrahedra; crisis, crises; hypothesis, hypotheses; polis, poleis; stigma, stigmata; topos, topoi; cyclops, cyclopes; Normally, however, they do not: colon, colons not *cola (except for the very rare technical term of rhetoric); pentathlon, pentathlons not *pentathla; demon, demons not *demones; climaxes, not *climaces.
A few of these also existed in Ancient Greek, such as crystallize, characterize, and democratize, but were probably coined independently in modern languages.
[35] Of the 500 most common words in English, 18 (3.6%) are of Greek origin: place (rank 115), problem (121), school (147), system (180), program (241), idea (252), story (307), base (328), center (335), period (383), history (386), type (390), music (393), political (395), policy (400), paper (426), phone (480), economic (494).