-er

The suffix '-er' in English is actually a merger of three historically distinct Germanic suffixes that converged in spelling and pronunciation through Old and Middle English.‍​‌​‌​‌​‌​‌​‌​‍​‍​‍​‌​‍​‍​‍​‌​‍​‍​‍​‌​‌​‌​‍​‌​‌​‌​‌​‌​‌​‌​‌​‌​‌ In Modern English, '-er' attaches to verbs to form agent nouns ('teach > teacher,' 'write > writer,' 'run > runner'), to adjectives and short adverbs to form comparatives ('fast > faster,' 'big > bigger,' 'soon > sooner'), and to place names to form inhabitant designations ('London > Londoner,' 'New York > New Yorker,' 'village > villager').

1. **Agent-noun '-er'.** This comes from Old English '-ere,' from Proto-Germanic *-ārijaz, which is probably an early borrowing from Latin '-ārius' into Germanic (perhaps as early as the first or second century CE through Roman-Germanic contact). Latin '-ārius' formed agent nouns like 'sicārius' (dagger-man, assassin) and 'agricultor' (farmer). The Germanic borrowing became a fully native suffix early, and by Old English times it was completely naturalised. Old English 'bæcere' (baker), 'bōcere' (scholar, from 'bōc,' book), 'wrītere' (writer). The suffix productively forms agent nouns from any verb: teacher, speaker, driver, singer, dancer, painter, baker, farmer, hunter, seller, buyer, worker, walker, runner, swimmer, cooker (rare; 'cook' is preferred as the person). It also attaches to nouns to form 'person associated with': Londoner, prisoner, engineer (via French), pensioner, villager, New Yorker. New coinages like 'blogger,' 'podcaster,' 'gamer,' 'coder,' 'texter,' 'uploader' show the suffix is fully alive.

2. **Comparative '-er'.** This comes from Old English '-ra' (adjectives) and '-or' (adverbs), from Proto-Germanic *-izô or *-ōzô, from Proto-Indo-European *-yōs / *-ōs — the same comparative marker that gave Latin '-ior' (as in 'superior,' 'inferior,' 'junior,' 'senior,' 'major,' 'minor'). Old English 'heardra' (harder), 'lengra' (longer), 'geongra' (younger). The suffix attaches to monosyllabic or short adjectives and adverbs to form the comparative degree: fast > faster, bright > brighter, big > bigger, happy > happier (with y > i), old > older, young > younger, long > longer, strong > stronger, tall > taller, high > higher, low > lower, small > smaller, short > shorter. Adjectives of two or more syllables usually take 'more' instead: 'more beautiful,' 'more interesting,' 'more terrible' — though some two-syllable adjectives allow both ('lovelier' / 'more lovely,' 'happier' / 'more happy,' 'quieter' / 'more quiet'). Adverbs similarly: soon > sooner, late > later, early > earlier, hard > harder (both adjective and adverb), fast > faster (both).

3. **Inhabitant / diminutive '-er'.** Some uses of '-er' form designations of people from a place or role, which may derive from an older Germanic '-ware' or may simply be a specialised use of the agent suffix. 'Londoner,' 'New Englander,' 'Icelander,' 'Highlander,' 'northerner,' 'southerner,' 'New Yorker,' 'Berliner,' 'Hamburger' (originally, inhabitant of Hamburg). It also appears in some informal or slang formations ('fiver' for a five-pound note, 'tenner' for ten, 'freshers' for first-year students, 'tweeter' for a speaker or person who tweets).

The three functions are easily distinguished by context because they attach to different parts of speech: agent '-er' attaches to verbs (forming nouns), comparative '-er' attaches to adjectives and adverbs (forming adjectives and adverbs), and inhabitant '-er' attaches to nouns (forming nouns). Occasionally a word is ambiguous between functions: 'faster' is either a comparative adjective ('a faster car') or an agent noun ('a religious faster'), distinguishable only by context.

Spelling rules for '-er' are standard for English suffixes. Final '-y' usually becomes '-i' before '-er' ('happy > happier,' 'lazy > lazier'), but only when the word is a comparative; agent nouns do not always show this change because they are newer coinages that preserve the verb spelling ('carry > carrier,' 'study > studier' - though -ier is preferred). Final '-e' is dropped ('wide > wider,' 'love > lover,' 'bake > baker'). Consonants after a short stressed vowel are doubled ('big > bigger,' 'thin > thinner,' 'run > runner,' 'shop > shopper'). These rules apply uniformly across the three functions.

Phonologically, '-er' is pronounced /ə/ (British) or /ər/ (American) — the schwa or rhotic schwa — and is always unstressed. The suffix does not alter the stress of the base word.

The agent-noun '-er' competes with a few other agent suffixes in English: '-or' (Latin-derived, as in 'actor,' 'creator,' 'doctor,' 'director,' 'inspector,' 'inventor,' 'professor,' 'translator'), '-ist' (Greek-derived, as in 'artist,' 'pianist,' 'scientist'), and '-ant' / '-ent' (Latin present participle, as in 'accountant,' 'assistant,' 'servant,' 'student,' 'president'). Generally '-er' is the default for native or naturalised English verbs, while '-or,' '-ist,' and '-ant' attach to Latinate or Greek-derived bases. Exceptions abound, especially doublets: 'adviser' / 'advisor' (both valid), 'conveyer' / 'conveyor,' 'practiser' / 'practitioner' (different forms).

The comparative '-er' has one remaining irregular form in English: 'good > better' (not 'gooder'), 'bad > worse' (not 'badder,' though 'badder' exists informally), 'far > farther' or 'further,' 'well > better,' 'little > less' or 'littler,' 'much' or 'many' > 'more.' These suppletive comparatives preserve older patterns from Proto-Germanic or earlier. 'Gooder' and 'badder' exist as non-standard forms; 'gooder' is childish or dialectal, 'badder' has become partially standard in colloquial speech.

Occasionally '-er' attaches to a whole noun phrase or clause to form a playful or informal agent noun: 'breadwinner,' 'game-changer,' 'home-owner,' 'law-maker,' 'pace-setter,' 'peace-maker,' 'fire-fighter,' 'match-maker.' These are compound agent nouns where '-er' attaches to the verb within the compound. Similarly: 'ear-splitter,' 'eye-opener,' 'mind-blower,' 'tear-jerker,' 'thrill-seeker.'

Representative agent '-er' nouns include: artist (ist), baker, banker, barber, boxer, broker, builder, burger (from Hamburger), butler (from bottler, originally), buyer, carrier, carpenter (via French), catcher, cleaner, coder, commuter, composer (but composer-of-music is Latinate), computer (agent-noun of compute), consumer, cooker (rare; usually 'cook'), dancer, designer, developer, doctor (or), driver, editor (or), employer, examiner, farmer, fighter, flyer, founder, gamer, gardener, gatherer, hacker, helper, hunter, immigrant (ant), interpreter, investor (or), joiner, keeper, killer, lawyer (via -er on 'law'), leader, learner, letter-writer, listener, logger, lover, maker, manager, manufacturer, marketer, member, messenger (from message + -er, with euphonic n), miner, mother, movie-goer, observer, officer, operator (or), organiser, owner, painter, passenger (from passage + -er), performer, photographer, pianist (ist), player, plumber, poet (from Greek; not -er), presenter, printer, producer, programmer, publisher, racer, reader, reporter, researcher, rider, rider, runner, saver, seeker, seller, server, settler, shooter, shopkeeper, singer, skater, skier, smoker, soldier (from Old French), speaker, spectator (or), sponsor, sprinter, stranger, student (ent), survivor (or), swimmer, talker, teacher, teenager, texter, thinker, traveller, trooper, trumpeter, user, visitor (or), voter, waiter, walker, whisperer, winner, worker, wrestler, writer. Representative comparative '-er' adjectives: bigger, blacker, bluer, brighter, broader, cheaper, clearer, closer, colder, cooler, darker, deeper, drier, drier, dumber, easier, faster, fatter, fewer, finer, flatter, fresher, fuller, funnier, greater, greener, happier, harder, harsher, healthier, heavier, higher, hotter, hungrier, kinder, larger, later, lazier, lighter, longer, louder, lower, luckier, madder, milder, nearer, newer, nicer, noisier, older, poorer, prettier, pricier, prouder, purer, quicker, quieter, quieter, redder, richer, riper, rougher, rounder, sadder, safer, sharper, shorter, sicker, simpler, slower, smaller, smarter, smoother, softer, sooner, sourer, stranger, stricter, stronger, sweeter, taller, tenser, thicker, thinner, tighter, tougher, truer, warmer, weaker, wealthier, wetter, whiter, wider, wiser, younger.