In English, the digraph usually represents either the voiced dental fricative phoneme (as in this) or the voiceless dental fricative phoneme (as in think). Occasionally, it stands for (as in Thailand, or Thomas). In the word eighth, it is often pronounced . In compound words, may be a consonant sequence rather than a digraph (as in the of lighthouse).
General description In standard English, the phonetic realization of the two dental fricative phonemes shows less variation than many other English consonants. Both are pronounced either interdentally, with the blade of the tongue resting against the lower part of the back of the upper teeth and the tip protruding slightly, or with the tip of the tongue against the back of the upper teeth. For some speakers these two positions are in free variation, while for other speakers they are in complementary distribution, the position behind the teeth being used when the dental fricative stands in proximity to an alveolar fricative or , as in myths () or clothes (). Lip configuration may vary depending on phonetic context. The vocal folds are abducted. The velopharyngeal port is closed. Air forced between tongue surface and cutting edge of the upper teeth (interdental) or inside surface of the teeth (dental) creates audible frictional turbulence.
The difference between and is normally described as a voiceless–voiced contrast, the distinction that native speakers are most aware of. They are also distinguished by other phonetic markers: the fortis is pronounced with more muscular tension than the lenis ; and is more strongly aspirated than , as can be demonstrated by holding a hand or putting a piece of paper or tissue in front of the mouth as they are spoken.
Phonology and distribution
In modern English, and are distinct phonemes, not merely allophones, as demonstrated by minimal pairs such as thigh:thy, ether:either, teeth:teethe. They are distinguished from the neighbouring labiodental fricatives, sibilants and alveolar stops by such minimal pairs as thought:fought/sought/taught and then:Venn/Zen/den.
The vast majority of words in English spelled with have , and almost all newly created words do. However, the high frequency of the function words, particularly the, means that is more frequent in actual use.
As a general rule, in initial position, is used except in certain function words; in medial position, is used except for certain foreign loan words; and in final position, is used except in certain verbs. A more detailed explanation follows.
Initial position Almost all words beginning with a dental fricative have . A small number of common function words (the Middle English anomalies mentioned below) begin with . The words in this group are: 1 definite article: the 4 demonstratives: this, that, these, those 2 personal pronouns each with multiple forms: thou, thee, thy, thine, thyself; they, them, their, theirs, themselves, themself 7 adverbs and conjunctions: there, then, than, thus, though, thence, thither (though in the United States thence and thither may be pronounced with initial The American Heritage Dictionary, 1969.) Various compound adverbs based on the above words: therefore, thereupon, thereby, thereafter, thenceforth, etc. A few words use an initial for (e.g. Thomas): see below.
Medial position Most native words with a medial have . Between vowels (including r-colored vowels): heathen, farthing, fathom, Worthington; and the frequent combination -ther-: bother, brother, dither, either, farther, father, further, heather, lather, mother, northern, other, rather, smithereens, slither, southern, together, weather, whether, wither; Caruthers, Netherlands, Witherspoon. Followed by : brethren. A few native words have a medial : The suffixes -y, -ly, -ing and -ed normally leave terminal unchanged: earthy, healthy, pithy, stealthy, wealthy, bothy (from booth); fourthly, monthly; earthing; frothed; but worthy and swarthy have . Some plurals have , as discussed in more detail below: cloths, baths etc. Compound words in which the first element ends or the second element begins with frequently have , as these elements would in isolation: bathroom, Southampton; anything, everything, nothing, something. The only other native words with medial would seem to be brothel (usually) and Ethel. Most loan words with a medial have . From Greek: Agatha, anthem, atheist, Athens, athlete, cathedral, Catherine, Cathy, enthusiasm, ether, ethics, ethnic, lethal, lithium, mathematics, method, methyl, mythical, panther, pathetic, sympathy From Latin: author, authority (though in Latin these had ; see below). Also names borrowed from or via Latin: Bertha, Gothic, Hathaway, Othello, Parthian From Celtic languages: Arthur (Welsh has medially: ); Abernathy, Abernethy, as an anglicization, though Gaelic has no . From Hebrew: Ethan, Jonathan, Bethlehem, Bethany, Leviathan, Bethel From German: Luther, as an anglicized spelling pronunciation (see below). Loanwords with medial : Greek words with the combination -thm-: algorithm, logarithm, rhythm. Exception : arithmetic . The word asthma may be pronounced or , though here the is usually silent. A few words have a medial for or (e.g. lighthouse): see below.
Final position
Nouns and adjectives Nouns and adjectives ending in a dental fricative usually have : bath, breath, cloth, froth, health, hearth, loath, mouth, sheath, sooth, tooth/teeth, width, wreath. Exceptions are usually marked in the spelling with a silent : tithe, lathe, lithe with . blithe can have either or . booth has in England but in Scotland and America. Verbs Verbs ending in a dental fricative usually have , and are frequently spelled with a silent : bathe, breathe, clothe, loathe, scathe, scythe, seethe, sheathe, soothe, teethe, tithe, wreathe, writhe. Spelled without : mouth (verb) nevertheless has . froth has whether as a noun or as a verb. The verb endings -s, -ing, -ed do not change the pronunciation of a in the final position in the stem: bathe has , therefore so do bathed, bathing, bathes; frothing has . Likewise clothing used as a noun, scathing as an adjective etc. The archaic verb inflection "-eth" has . Others with has either or (see below), as do its compounds: within, without, outwith, withdraw, withhold, withstand, wherewithal, etc.
Plurals Plural after may be realized as either or : Some plural nouns ending in , with a preceding vowel, have , although the singulars always have ; however, a variant in will be found for many of these: baths, moths, mouths, oaths, paths, sheaths, truths, wreaths, youths exist in both varieties; clothes always has (if not pronounced ). Others have only /θs/: azimuths, breaths, cloths, deaths, faiths, Goths, growths, mammoths, myths, smiths, sloths, zeniths, etc. This includes all words in 'th' preceded by a consonant (earths, hearths, lengths, months, widths, etc.) and all numeric words, whether preceded by vowel or consonant (fourths, fifths, sixths, sevenths, eighths , twelfths, fifteenths, twentieths, hundredths , thousandths). Booth has in the singular and hence in the plural for most speakers in England. In American English, it has in the singular and or in the plural. This pronunciation also prevails in Scotland.
Grammatical alternation In pairs of related words, an alternation between and is possible, which may be thought of as a kind of consonant mutation. Typically appears in the singular of a noun, in the plural and in the related verb: cloth , clothes , to clothe . This is directly comparable to the or alternation in house, houses or wolf, wolves. It goes back to the allophonic variation in Old English (see below), where it was possible for to be in final position and thus voiceless in the basic form of a word, but in medial position and voiced in a related form. The loss of inflections then brought the voiced medial consonant to the end of the word. Often a remnant of the old inflection can be seen in the spelling in the form of a silent , which may be thought of synchronically as a marker of the voicing.
Regional differences in distribution
The above discussion follows Daniel Jones' English Pronouncing Dictionary, an authority on standard British English, and Webster's New World College Dictionary, an authority on American English. Usage appears much the same between the two. Regional variation within standard English includes the following: The final consonant in with is pronounced (its original pronunciation) in northern Britain, but in the south, though some speakers of Southern British English use before a voiceless consonant and before a voiced one. A 1993 postal poll of American English speakers showed that 84% use , while 16% have (Shitara 1993). (The variant with is presumably a sandhi development.) In Scottish English, is found in many words which have further south. The phenomenon of nouns terminating in taking plurals in does not occur in the north. Thus the following have : baths, mouths (noun), truths. Scottish English does have the termination in verb forms, however, such as bathes, mouths (verb), loathes, and also in the noun clothes, which can be realized without . Scottish English also has in with, booth, thence etc., and the Scottish pronunciation of thither, almost uniquely, has both and in the same word. Where there is an American-British difference, the North of Britain generally agrees with the United States on this phoneme pair. Some dialects of American English use at the beginning of the word "thank".
History of the English phonemes
Germanic origins Proto-Indo-European (PIE) had no dental fricatives, but these evolved in the earliest stages of the Germanic languages. In Proto-Germanic, and were separate phonemes, usually represented in Germanic studies by the symbols *đ and *þ. *đ () was derived by Grimm's law from PIE *dʰ or by Verner's law (i.e. when immediately following an unstressed syllable) from PIE *t. *þ () was derived by Grimm's law from PIE *t. In West Germanic, the Proto-Germanic *đ shifted further to *d, leaving only one dental fricative phoneme. However, a new appeared as an allophone of in medial positions by assimilation of the voicing of the surrounding vowels. remained in initial and presumably in final positions (though later terminal devoicing would in any case have eliminated the evidence of final ). This West Germanic phoneme, complete with its distribution of allophones, survived into Old English. In German and Dutch, it shifted to a , the allophonic distinction simply being lost. In German, West Germanic *d shifted to in what may be thought of as a chain shift, but in Dutch, *þ, *đ and *d merged into a single .
The whole complex of Germanic dentals, and the place of the fricatives within it, can be summed up in this table:
PIE Proto-Germanic West Germanic Old English German Dutch Notes *t *þ *[þ] Original *t in initial position, or in final position after a stressed vowel *[đ] Original *t in medial position after a stressed vowel *đ *d Original *t after an unstressed vowel *dʰ Original *dʰ in all positions *d *t *t or Original *d in all positions
Note that this table shows only the basic rules. The actual developments in all of the mentioned languages are more complicated (due to dialectal variation, peculiar developments in consonant clusters, etc.). For more on these phonemes from a comparative perspective, see Grammatischer Wechsel. For the developments in German and Dutch see High German consonant shift.
Old English
Thus English inherited a phoneme in positions where other West Germanic languages have and most other Indo-European languages have : English three, German drei, Latin tres.
In Old English, the phoneme , like all fricative phonemes in the language, had two allophones, one voiced and one voiceless, which were distributed regularly according to phonetic environment. (like and ) was used between two voiced sounds (either vowels or voiced consonants).