2. According to the presence of secondary parts simple sentences should be divided into unextended (unexpanded) and extended (expanded).

The unexpanded simple sentence, a monopredicative sentence, which includes only obligatory nominative parts (e.g. He is a student.). The expanded simple sentence includes also some optional parts which do not violate the syntactic status of the simple sentence, i.e. do not make it into a composite or semi-composite sentence (e.g. He is a good student.).

The semantic classification of simple sentences should be effected at least on the three bases: first, on the basis of the subject categorial meanings; second, on the basis of the predicate cate gorial meanings; third, on the basis of the subject-object relation.

3. According to the type of the subject simple sen­tences are divided into personal and impersonal (e.g. It drizzles; There is no use crying over spilt milk.). The further division of the personal sentences is into human and non-human; human — into definite (e.g. I know it.) and in­definite (e.g. One never knows such things for sure.); non-human — into animate (e.g. A cat entered the room.) and inanimate (e.g. The wind opened the door.). The further essential division of impersonal sentences is into factual (e.g. It drizzles.) and perceptional (e.g. It looks like rain.).

4. According to the type of the predicate simple sentences are divided into process featuring (“verbal”) and substance featuring (“nominal”); process featuring sentences are further subdivided into actional, e.g.: I play ball; and statal, e.g.: I enjoy your party; substance featuring sentences are further subdivided into factual, e.g.: She is clever; and perceptional, e.g.: She seems to be clever. As the examples show, the differences in subject categorial meaning are sustained by obvious differences in the subject-predicate combinability.

5. According to the type o£ the subject-object rela­tion simple sentences should be divided into subjective (e.g. I live in Moscow.), objective (e.g. I’m reading a book.) and neutral (e.g. I’m reading.) or "potentially" objective, capable of implying both the transitive action of the syntactic per­son and the syntactic person's intransitive characteristic