It was Pāṇini, known for his Sanskrit grammar, who described it in his 'Eight Chapters'. The concept referred to the length of vowels. In Indo-European linguistics it came to be known as zero grade (= no vowel), full grade (= short vowel) and lengthened grade (= long vowel). An often cited example is pater, the Greek word for father. The singular accusative is patera (with a short stressed<e>), the sing. nominative is pater (with a long stressed <e>) and the genitive is patros (with no e-vowel). So patros illustrates zero grade, patera exemplifies full grade and pater demonstrates lengthened grade. These forms of the Greek noun pater display quantitative gradation. But there's also qualitative gradation as in sing, sang, sung and song.
The gradation types discussed so far serve morphological purposes, they denote a change in case (Greek pater), tense (sing, sang, sung), transitivity (rise, raise) or word class (sing, song). By the end of the 19th c., however, the term had acquired an additional meaning. In Henry Sweet's Elementarbuch des gesprochenen Englisch of 1885 we find a chapter on "Abstufung" (p. xxix ff.). In the English version of that book called A Primer of Spoken English of 1890 the term Abstufung is translated as "gradation" (p. 13). It is in this book that Sweet characterises gradation as a "totally new subject" (p. x). In his Handbook of Phonetics of 1877 he had made no mention of the term.
This 'new' meaning of gradation does not imply that the traditional meaning has come out of use - quite the contrary, see e.g. W. W. Skeat in his Principles of English Etymology, vol. I, of 1892, where he uses the term in its traditional sense (see his ch. X).
Daniel Jones took up the concept of gradation in the Sweetian sense, e.g in his Paris lecture which he delivered in January 1912 to the Guilde Internationale. The lecture to an audience of phonetic laymen was entitled "The teaching of English pronunciation to French students". Jones applied the concept pretty much in the same sense as Sweet had done when the former talked about "the treatment of small words like have, from, but, should, the, them, of and a large number of others." Jones went on to say: "[...] the weak forms are used when the words are unemphatic or in unimportant positions. [...] The weak forms all have the weak neutral vowel [ə]." The term gradation, however, was not used until later in his Outline of English Phonetics (thanks to Jack Windsor Lewis (= JWL) for drawinɡ my attention to the book). In the following table you find all major editions and the paragraph in which the term is first mentioned.
Here's a scan of the relevant paragraphs taken from the 9th ed. of his Outline:
In addition to schwa Jones records the use of weakforms with /i/ (e.g. /ði/) and /u/ (e.g. /tu/) (I use Jones's set of symbols here).
All of us are aware of the fact that, more often than not, one and the same English word may be pronounced in more than one way. This applies not only to the so-called 'small' words like and (/ænd, ənd, ən, nd, n/) but also to 'bigger' ones such as particular (/pəˈtɪkjʊlə, pəˈtɪkjələ, pˈtɪkjələ, pˈtɪklə, .../) or police (/pəˈliːs, pliːs/). The terms strong form and weak form (overwhelmingly spelled as two words) are widely accepted for describing the changes of /ænd/ to, e.g., /ən/. But what are we to call the comp'r'bl changes observable in /pəˈtɪkjʊlə/ -> /pˈtɪkjələ/, in /əʊnli/ -> /əʊni/ or in comp'r'bl ?
Very often the phonetic concept of weakforms is tied to the grammatical concepts of lexical and function (or grammatical, structural, synsemantic) words in the literature (see e.g. Cruttenden (20087), Gimson's Pronunciation of English, p. 266). Cruttenden writes:
Lexical words [...] generally have in connected speech the quantitative pattern of their isolate form and therefore retain some measure of prominence based on the occurrence of a full vowel even when no pitch prominence is associated with them.The list that follows contains not only function words, but also 2 lexical words: saint and sir.
However, many function words have two or more qualitative and quantitative patterns according to whether they are unaccented (as is usual) or accented (in special situations or when said in isolation). As compared with the accented realizations of these words (the strong forms), the unaccented weak forms of those words show reductions of the length of sounds, obscuration of vowels towards /ə, ɪ, ʊ/ [Cruttenden's symbols] and the elision of vowels and consonants."
What characterises functions words phonetically is, according to the author, this:
- ≥2 qualitative and quantitative sound patterns [I would say 'qualitative and/or quantitative'];
- the selection of a pattern depends on whether the function word is accented (= the strongform is chosen) or unaccented (= the weakform is used);
- characteristic features of a weakform sound pattern are:
- sound length reduction,
- vowel quality obscuration, and/or
- elision of vowels and/or consonants.
- there are 2 qualitative sound patterns;
- the form /əʊni/ is selected when the word is unaccented;
- as a consonant is elided, feature 3.3 applies here.
I'd like to get rid of the grammar-centred terminology and rather concentrate on phonetic distinctions. The best ensemble of such features that I've detected in the literature so far is to be found in an online article by Jack Windsor Lewis with the title "Weakform Words and Contractions for the Advanced EFL User" and in his book A Guide to English Pronunciation (1969). The following features try to describe the differences between strongforms and weakforms:
- there are ≥2 sound patterns of a word with different sets of phonemes;
- one of the forms (= strongform) is used when sentence rhythm or tempo call for its use or the speaker wants to accentuate the word, else one of the weakforms may be used;
- the phonemic difference between the forms must not be affected by contextual effects such as assimilation (/kən ɡəʊ/ -> /kəŋ ɡəʊ/) or elision (/kɑːnt teɪk/-> /kɑːn teɪk/);
- the strongform represents the canonical2 pronunciation of a word; all alternant weakform pronunciations are derived from the canonical version (JWL via personal communication - slightly re-phrased);
- there's a subgroup of forty-odd words with one or more grammatico-stylistical variant pronunciations; this subgroup is called "special weakform words";
- the selection of a weakform or a strongform of a word which belongs to the subgroup is more or less obligatory.
Shocking, is it not?
P.S.: See also JWL's blogs no. 399 and no. 400.
1 Grimm, J. (18222), Deutsche Grammatik, vol. 1, (Göttingen).
2 By canonical pronunciation is meant
- a) the isolated, non-embedded, heavily stressed/accented, prominent, generally accepted pronunciation, which is often used in definitional, metalinguistic discourse.
- b) If the canonical pronunciation is sententially embedded, then
- all the pronounceable sounds of the word are in fact pronounced and
- the particular pronunciation of the word is not confined to being embedded in a particular slot of the cotext and
- the pronunciation is not the result of an assimilatory or elisional process.