The branch of lexicology that is devoted to the study of meaning is known as semasiology.
Meaning is one of the most difficult problems in the theory of language and it has been the topic of interminable discussions. There is no universally accepted definition of meaning. All the linguists agree that word-meaning is not homogeneous but it is made up of various components. They are usually described as types of meaning- grammatical and lexical.
We notice that the words worked, ended, played, etc., those denoting different actions, have a common element - the grammatical meaning of past tense.
The words girls, tables, plates have the common element of plurality.
In the word-forms sister's, worker's, etc. the common element is the case meaning.
Thus, grammatical meaning may be defined as the component of meaning which is always seen in identical sets of individual forms of different words.
Modern linguists acknowledge that some elements of grammatical meaning can be revealed by definite position of the linguistic unit in relation to other linguistic units, i.e. by its distribution. So, word-forms reads, plays, asks, etc. 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, usually, today , etc.
The distribution of other word-forms reveals another grammatical meaning: took, repeated, asked are always found not only after the pronouns he, she, it, but also after I, you, we, they, and before the adverbs yesterday, last week, a year ago, etc.