The actuality of the present thesis

II.4. Synthetic types
The number of morphemes used for deriving word-forms in Modern English is very small (much smaller than either in German or in Russian, for instance). They may be enumerated in a very short space.
There is the ending -s (-es), with three variants of pronunciation, used to form the plural of almost all nouns, and the endings -en and -ren, used for the same purpose in one or two words each, viz. oxen, brethren (poet.), children.
There is the ending -'s, with the same three variants of pronunciation as for the plural ending, used to form what is generally termed the genitive case of nouns.¹
For adjectives, there are the endings -er and -est for the degrees of comparison.
For verbs, the number of morphemes used to derive their forms is only slightly greater. There is the ending -s (-es) for the third person singular present indicative, with the same three variants of pronunciation noted above for nouns, the ending -d (-ed) for the past tense of certain verbs (with three variants of pronunciation, again), the ending -d (ed) for the second participle of certain verbs, the ending -n (-en) for the second participle of certain other verbs, and the ending -ing for the first participle and also for the gerund.
Thus the total number of morphemes used to derive forms of words is eleven or twelve, which is much less than the number found in languages of a mainly synthetical structure.
It should also be noted that most of these endings are mono-semantic, in the sense that they denote only one grammatical category and not two or three (or more) at a time, as is the case in synthetic languages. For example, the plural -s (or -es) denotes only the category of plural number, and has nothing to do with any other grammatical category, such as case.
It would, however, mean oversimplifying matters if we were to suppose that all English inflectional morphemes are mono-semantic. This is certainly not the case with the -s (-es) of the third person singular. It expresses at least three grammatical categories: person (third), number (singular), and mood (indicative). In certain verbs it also expresses the category of tense: thus, in the form puts only the -s shows that it is a present-tense form.The said elements of language, as we have stated elsewhere, should beyond dispute be considered signemic units of language, since they are functionally bound. They form the secondary line of speech, accompanying its primary phonemic line (phonemic complexes). On the other hand, from what has been stated about the morpheme proper, it is not difficult to see that the morphemic interpretation of suprasegmental units can hardly stand to reason. Indeed, these units are functionally connected not with morphemes, but with larger elements of language: words, word-groups, sentences, supra-sentential constructions.
On the basis of grammatical alternation, "additive" morphemes and "replacive" morphemes are distinguished. Interpreted as additive morphemes are outer grammatical suffixes, since, as a rule, they are opposed to the absence of morphemes in grammatical alternation. Cf. look+ed; small+er, etc. In distinction to these, the root phonemes of grammatical interchange are considered as replacive morphemes, since they replace one another in the paradigmatic forms. Cf. dr-i-ve — dr-o-ve — dr-i-ven; m-a-n — m-e-n; etc.
It should be remembered that the phonemic interchange is utterly unproductive in English as in all the Indo-European languages. If it were productive, it might rationally be interpreted as a sort of replacive "infixation" (correlated with "exfixation" of the additive type). As it stands, however, this type of grammatical means can be understood as a kind of suppletivity (i.e. partial suppletivity).
On the basis of linear characteristic, "continuous" (or "linear") morphemes and "discontinuous" morphemes are distinguished.
By the discontinuous morpheme, opposed to the common, i.e. uninterruptedly expressed, continuous morpheme, a two-element grammatical unit is meant which is identified in the analytical grammatical form comprising an auxiliary word and a grammatical suffix. These two elements, as it were, embed the notional stem; hence, they are symbolically represented as follows:
be ... ing — for the continuous verb forms (e.g. is going); have ... en — for the perfect verb forms (e.g. has gone); be ... en — for the passive verb forms (e.g. is taken).
It is easy to see that the notion of morpheme applied to the analytical form of the word violates the principle of the identification of morpheme as an elementary meaningful segment: the analytical "framing" consists of two meaningful segments, i.e. of two different morphemes. On the other hand, the general notion "discontinuous constituent", "discontinuous unit" is quite rational and can be helpfully used in linguistic description in its proper place.