2.1 Grammatical meaning of the word
Every word has two aspects: the outer aspect (its sound form) and the inner aspect (its meaning). Sound and meaning do not always constitute a constant unit even in the same language.
It is more or less universally recognised that word-meaning is not homogeneous but is made up of various components the combination and the interrelation of which determine to a great extent the inner facet of the word. These components are usually described as types of meaning. The two main types of meaning that are readily observed are the grammatical and the lexical meanings to be found in words and word-forms.
We notice, e.g., that word-forms, such as girls, winters, joys, tables etc. though denoting widely different objects of reality have something in common. This common element is the grammatical meaning of plurality which can be found in all of them.
Thus grammatical meaning may be defined ,as the component of meaning recurrent in identical sets of individual forms of different words, as, e.g., the tense meaning in the word-forms of verbs (asked, thought, walked, etc.) or the case meaning in the word-forms of various nouns (girl’s, boy’s, night’s etc.).
In a broad sense it may be argued that linguists who make a distinction between lexical and grammatical meaning are, in fact, making a distinction between the functional (linguistic) meaning which operates at various levels as the interrelation of various linguistic units and referential (conceptual) meaning as the interrelation of linguistic units and referents (or concepts).
In modern linguistic science it is commonly held that some elements of grammatical meaning can be identified by the position of the linguistic unit in relation to other linguistic units, i.e. by its distribution. Word-forms speaks, reads, writes have one and the same grammatical meaning as they can all be found in identical distribution, e.g. only after the pronouns he, she, it and before adverbs like well, badly, to-day, etc.
It follows that a certain component of the meaning of a word is described when you identify it as a part of speech, since different parts of speech are distributionally different (cf. my work and I work).
2.2 Lexical meaning of the word
Comparing word-forms of one and the same word we observe that besides grammatical meaning, there is another component of meaning to be found in them. Unlike the grammatical meaning this component is identical in all the forms of the word. Thus, e.g. the word-forms go, goes, went, going, gone possess different grammatical meanings of tense, person and so on, but in each of these forms we find one and the same semantic component denoting the process of movement. This is the lexical meaning of the word which may be described as the component of meaning proper to the word as a linguistic unit, i.e. recurrent in all the forms of this word.
The difference between the lexical and the grammatical components of meaning is not to be sought in the difference of the concepts underlying the two types of meaning, but rather in the way they are conveyed. The concept of plurality, e.g., may be expressed by the lexical meaning of the world plurality; it may also be expressed in the forms of various words irrespective of their lexical meaning, e.g. boys, girls, joys etc. The concept of relation may be expressed by the lexical meaning of the word relation and also by any of the prepositions, e.g. in, on, behind etc.
It follows that by lexical meaning we designate the meaning proper to the given linguistic unit in all its forms and distributions, while by grammatical meaning we designate the meaning proper to sets of word-forms common to all words of a certain class. Both the lexical and the grammatical meaning make up the word-meaning as neither can exist without the other. That can be also observed in the semantic analysis of correlated words in different languages. E.g. the Russian word сведения is not semantically identical with the English equivalent information because unlike the Russian сведения the English word does not possess the grammatical meaning of plurality which is part of the semantic structure of the Russian word.
2.2.1 Part-of-Speech Meaning
It is usual to classify lexical items into major word-classes (nouns, verbs, adjectives and adverbs) and minor word-classes (articles, prepositions, conjunctions, etc.).
All members of a major word-class share a distinguishing semantic component which though very abstract may be viewed as the lexical component of part-of-speech meaning. For example, the meaning of “thingness” or substantiality may be found in all the nouns e.g. table, love, sugar, though they possess different grammatical meanings of number, case, etc. It should be noted, however, that the grammatical aspect of the part-of-speech meanings is conveyed as a rule by a set of forms. If we describe the word as a noun we mean to say that it is bound to possess a set of forms expressing the grammatical meaning of number (table — tables), case (boy, boy’s) and so on. A verb is understood to possess sets of forms expressing, e.g., tense meaning (worked — works), mood meaning (work! — (I) work) etc.
The part-of-speech meaning of the words that possess only one form, e.g. prepositions, some adverbs, etc., is observed only in their distribution (to come in (here, there)).
One of the levels at which grammatical meaning operates is that of minor word classes like articles, pronouns, etc.
Members of these word classes are generally listed in dictionaries just as other vocabulary items, that belong to major word-classes of lexical items proper (e.g. nouns, verbs, etc.).
One criterion for distinguishing these grammatical items from lexical items is in terms of closed and open sets. Grammatical items form closed sets of units usually of small membership (e.g. the set of modern English pronouns, articles, etc.). New items are practically never added.
Lexical items proper belong to open sets which have indeterminately large membership; new lexical items which are constantly coined to fulfil the needs of the speech community are added to these open sets.
The interrelation of the lexical and the grammatical meaning and the role played by each varies in different word-classes and even in different groups of words within one and the same class. In some parts of speech the prevailing component is the grammatical type of meaning. The lexical meaning of prepositions for example is, as a rule, relatively vague (one of the students, the roof of the house). The lexical meaning of some prepositions, however, may be comparatively distinct (in/on, under the table). In verbs the lexical meaning usually comes to the fore although in some of them, the verb to be, e.g., the grammatical meaning of a linking element prevails (he works as a teacher and he is a teacher).