O (letter)

O, o is a letter of the Latin alphabet. It is the fifteenth letter of most variants, being placed after N and before P, as is the case for instance in the English alphabet. Its English name is pronounced [ˈəʊ] or [ˈoʊ], like the exclamation oh!

Use in English

	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R	S	T	U	V	W	X	Y	Z
Use in English
Alphabetical word list
Retroalphabetical list
Common misspellings

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o represents various (usually) back vowel sounds. It is very versatile, with three irregular sounds, move (oô), wolf (ù) and women (í: the accents show stress and pronunciation: see English spellings). But normally:

The short sound: dóg, sóft, góne, sóng, lóng, alóng, cróss, lóst, hóp, dóck, ród, nód, sóft, nót negative = knót tie, dóll, knóll (cf. pôll, tôll).

The long sound corresponds to the word ôh (in which the h is silent), a diphthong which approximates to schwa followed by the sound of ù/oò: bôat, flôat, hôpe, strôve, thôugh, nôse, gôes, gô, nô, lôw, knôw, grôw, thrôw, ôcean, prôven (though this can be pronounced *prûven, with the same sound as in prove and move), phãrôah Egypt = Fãrôe Islands, ôpen, sôap, unmarked and unstressed in cháperôn (sh-), BrE brôoch. Compare Hólland and Pôland.

Compare Jóhn and Jôan: it is the latter that has the ôh sound.

Before l for some BrE and antipodean speakers the long sound is more like ó plus ù in words like sôul spirit = sôle only, fish, Pôland, strôll, tôll (cf. dóll), bôwl (cf. hòwl). Compare the two ôs in Rôlling Stônes. Only the long sound can end a word: tornâdô, Plâtô, lîdô, agô.

ò is pronounced like ú in sún, and occurs before gh, m, n, th, v especially: òther, mòther, bròther, wòrry, wònder, hòney, mòney, amòng, îronmònger, frònt, gòvern, òven, còver, còmpany, cònstable, lòver, shòvel, dòzen, nòthing, BrE còlour, AmE còlor hue (cf. cóllar shirt). It is a very common mistake for learners to pronounce this ò like the ó in óff, especially those whose mother tongue is Spanish, in words like gòvernment, còúntry, and, of course, Colòmbia (= Colúmbia).

The sound is a stressed schwa in American English (IPA ə), and ʌ in British English.

ú is more common in monosyllables than ò: sóck, sôak, súck; cót, côat, cút.

When ò does occur in monosyllables, there is a typical pattern with v: lòve, abòve, glòve, dòve, shòve; and also tòn, òne 1 = wòn victor (*wún), dòes, dòth.

ò often combines with ú, rendering itself redundant, as in yoúng, noúrish, floúrish, Doúglas, roúgh, coúple, doúble, troúble (cf. búbble), coúntry, coúntryside, soúthern (cf. sòuth).

That is different from the còw diphthong sound in còunt number, còunty district, vòw, clòud, òut, vòwel, tòwer, dòubt, òwl, fòwl bird = fòul horrible, tòwel, dròught, sòuth, cròwd, sòund, nòw, hòwl (cf. bôwl) and before (e)r: pòwer, tòwer, glòur, dòwry, flòwer plant = (for most speakers) flòur dough.

òu is in final position only in thòu (dh-). There is also oû: yoû, coûp revolution (= coô bird), soûp (p pronounced) and ou as w from French as in Ouagadoûgou (*Wágadûgu) and ouìja-bŏard (*uwêejəbŏrd).

ŏ is very common, usually in ŏr, but also ŏur, ŏugh and ŏa (and also spelt åu, åw, etc.): ŏr, nŏrth, pŏrt, lŏrd, swŏrd, mŏrning, ŏught, bŏught, sŏught, brŏught, bŏrn, swŏrn, hŏrse, cŏrd rope = chŏrd music, Nŏra, Dŏra, Flŏra name = flŏra flowers (cf. fåuna), Pŏrtugal, yŏur, yŏurs, cŏurse, sŏurce, resŏurce, fŏur, gŏurd, mŏurn, abrŏad, brŏad, bŏar, ŏar.

This sound is still found sometimes in a "posh" pronunciation of ŏff and ŏften (for óff and óften), though this is probably dying out.

When this sound has stress, -ŏre is usual at the end of a word: deplŏre, swŏre, bŏre, mŏre and ŏre.

But: abhŏr, fŏur 4 = fŏr sake, and pŏre skin = pŏur drink = pŏor misery (though poôr for many speakers).

-or is, however, usually schwa at the end of a word, -ər, showing an agent (as with -er): dóctor, tráctor, fáctor, objéctor, léctor, próctor, projéctor, and the verb héctor, from the name Héctor.

-ŏrr is found only in names: Cŏrr, Ŏrr (= ŏr alternative), Andŏrra, which rhymes with Pandŏra in AmE - BrE Andórra, cf. Dórrit.

But or is pronounced with the longer schwa-like sound of ër and ür after w: wörd, wörld, wörm, wörth, wörk, wörse, wörst - and also in attörney. It is a common mistake for learners to pronounce it the same as ŏr; in fact it is the same sound as in ëarth, fïrst, nërvous, türn, chürn, bürn, cërtain and hürt. The ŏ sound after w is in fact spelt å: wårn, Wårner, wårm, wåll, wålnút, wåter (cf. wâfer, wâit, wâve; ẁhat, ẁasp, ẁad).

The ër sound is spelt öur in jöurney, jöurnal, adjöurn, cöurteous, cöurtesy politeness (cf. cürtsey bow), scöurge, böurbon and unstressed in Lúxembourg. And, directly from French, öeuvre (*ërvrə, sometimes written œuvre).

ŏ forms diphthongs with i and y: cŏin, bŏy, tŏy, jŏint, jŏin, vŏid, ŏil, fŏil, jŏy, destrŏy, állŏy, almost always y at the end of a word and i in other positions - very often before l or n. But names can ignore this rule: Jŏyce, Rôlls Rŏyce, Flŏyd, Bŏyd.

oi is weak, schwa, for most speakers in pŏrpoise, tŏrtoise.

In some words from French, oi retains the pronunciation wà: sávoir fãire, réservoir, ábbatoir, *sávwà(r)-féə(r), *rézə(r)vwà(r), ábətwà(r).

oo

oo is a special case, with five different pronunciations (without counting accidental clashes of two regular pronunciations such as in coóperate and coŏrdinate, both with the prefix cô-, which can be marked with a hyphen: co-operâtion). It functions like a letter in its own right:

1. Like ú in fún or ò in mòther, only in blòod and flòod.

2. Like ô in gô, only in BrE brôoch and Rôosevelt.

3. As ŏor instead of ŏr at the end of monosyllables: dŏor, pŏor, flŏor (though some pronounce these -oôr).

4. Like ù in pùt, fùll: coòk, soòt, foòt, woòd tree (= woùld if), goòd (cf. coùld), oòmph.

5. Most commonly, like û in illûminate - but never with the invisible consonantal 'y' sound which is so often heard at the beginning of û as in tûne (*tyûne).

Usually before voiced consonants: broôd, soôn, moôn, foôd, boôn, toôl, foôl, stoôl, oôh!, oôdles, choôse (*choôz), but also before unvoiced consonants: loôse (*lûce), hoôp, loôp, stoôp.

Compare poôl water, billiards and pùll push, pronounced *poòl.

toô also = tŵo number = to preposition are pronounced the same - although to is usually weak, so it normally has the schwa sound. The same oô sound is found spelt with one o in do, move and prove.

Example: 'Hê has hád toô many drínks - díd he háve to drínk tŵo toô many, do yoû thínk? What moved hím to?’ ‘But cán yoû prove it?’

ough

ough has nine different pronunciations:

úff: enoúgh, toúgh, roúgh, sloúgh skin (*ínúff, etc.)

óff: tróugh, cóugh, Góugh, Bóugh (*tróff, etc.)

ŏ, before t: nŏught, thŏught, ŏught (*nåwt, thåwt, åwt)

û: throûgh pass, throughòut (= threŵ throw, threŵ òut)

òu: bòugh, dròught, slòugh swamp = Slòugh England (all rhyming with hòw and nòw)

ô: dôugh, thôugh, althôugh (all rhyming with nô and gô)

schwa, (though for AmE speakers, these can also be ô): bòrough (*búrə), thòrough (*thúrə), Scàrborough (cf. Édinburgh, both -brə in BrE)

úp: only in híccough (alternative spelling of híccup)

IPA ɒχ: only in lóugh (Irish spelling of lóch, same pronunciation)

Irregular o’s

Spelling	Pronunciation
approve	*approôv
Boer	*Bûer
bosom	*bùzəm
canoe	*canoô
croissant	*kwússón (French nasal -ón)
do	*doô
lasso	*lássoô
Lesotho	*Lesûtu
lose	*loôz
move	*moôv
prove	*proôv
shoe foot	shoô away
to preposition	toô also, many = tŵo number
tomb	*toôm
who	Hû person (cf. Dóctor Who)
whose	*hoôz
wolf	*wùlf (cf. Bèowulf)
woman	*wùmən
women	*wímmin
Worcester	*Wùstər

With do (*doô), we can compare dôe animal = dôugh bake.

to preposition = toô many, also = tŵo number, compare tôe foot, toúgh strong = túff rock.

-ous versus -us

-ous forms adjectives, -us forms nouns.

Adjectives: pàrlous, treméndous, màrvellous, trémulous, cöurteous, magnánimous, précious, disāstrous (minus the e of disāster). An exception is Thelônious Mònk.

Nouns (especially names): ábacus, sýllabus, ómnibus (whence bús), nímbus, cûmulus, óctopus, sánctus, fôcus, crôcus, Màrcus, Catúllus, Horâtius (*Horâyshəss).

The noun suffix -our becomes -or- before -ous: hûmorous, glámorous.

òw and ôw

òw stressed in monosyllables: sòw pig, hòw, nòw, bròwn, còw, fròwn, bòw down, vòw, wòw, AmE plòw (BrE plòugh) and in: còward, còwardly, glòwer, flòwer, pòwer, Gòwer, shòwer, nòwadays.

ôw stressed in monosyllables: sôw seed (= sew needle) lôw, môw, tôw pull (= tôe foot) and unstressed at the end of words of two syllables: yéllôw, shállôw, hóllôw, gállôws, nárrôw, bórrôw, árrôw, fúrrôw, fállôw.

oe and eo

oê, from Greek 'οι', is quite rare. It can be written as a single letter, œ, but this is unusual nowadays, and e alone is often used instead, especially in America. But one still occasionally sees Phœbe, fœtus, œnology, Œdipus, phœnix bird (= Phoênix Arizona), œstrogen instead of Phoêbe, foêtus, oênology, Oêdipus, phoênix, oêstrogen. And, from French, there is œuvre (*ërvrə).

gôes (cf. dòes do, dôes animals) and the plurals tôes, potâtoes, AmE tomâtoes, BrE tomàtoes, peccadíllôes are of course not Greek 'οι' and just have the ô sound. But not all plurals have the e: volcânos, tornâdos, hâlos, concërtos (consh-). The longer the word has been in the English language, the more likely it is to have -ôes; there is alas no other rule.

pêople has the same vowel sound as œ, but with the letters reversed, and the o completely redundant, as it is also in léopard and jéopardy (cf. jéalousy), and in the names Groèning and Boèhner, which both have, remarkably, the ây sound.

-ôl

A common ending is -ôl, spelt thus in contrôl but not in monosyllables, a list of which can be found at L.

As noted above, for some speakers, final -ôl is pronounced more like 'óùl' than the more standard IPA [əʊl].

Scientific uses

• o- prefix: old chemical notation, ortho
• O: order of (limited by a constant multiple of what follows in round brackets)
• o: tending to a zero multiple of what follows in round brackets