We should probably also class among sentences with a simple nominal predicate the sentences in which the function of predicate is performed by a participle. Sentences of this type received very little attention until quite recently, when they were discussed in a grammar by Prof. N. Irtenyeva 1 and in a dissertation by Y. Komissarova

Predicates may be classified in two ways, one of which is based on their structure (simple and compound), and the other on their morphological characteristics (verbal and nominal). If we take the structural classification as the basic one we obtain the following types

The question now arises, how are we to define the subject of a sentence? The question may also be put in a different way: what criteria do we practically apply when we say that a word (or, sometimes, a phrase) is the subject of a sentence?

It is common in grammatical theory to distinguish between main and secondary parts of a sentence. Besides these two types there is one more — elements which are said to stand outside the sentence structure.

In studying the structure of a sentence, we are faced with a problem which has been receiving ever greater attention in linguistic investigations of recent years. This is the problem of dividing a sen-tenсe into two sections, one of them containing that which is the starting point of the statement, and the other the new information for whose sake the sentence has been uttered or written. This has been termed "functional perspective". We will illustrate it by a pimple example. Let us take this sentence from a contemporary novel: I made the trip out here for curiosity, just to see where you were intending to go.

It has been usual for some time now to classify sentences into two-member and one-member sentences. 1 This distinction is based on a difference in the so-called main parts of a sentence. We shall therefore have to consider the two problems, that of two-member and one-member sentences and that of main parts of the sentence, simultaneously.

We will now study the structure of the simple sentence and the types of simple sentences. First of all we shall have to deal with the problem of negative sentences. The problem, briefly stated, is this: do negative sentences constitute a special grammatical type, and if so, what are its grammatical features? In other words, if we say, "This is a negative sentence," do we thereby give it a grammatical description?

The problem of classification of sentences is a highly complicated one, and we will first consider the question of the principles of classification, and of the notions on which it can be based.

The notion of sentence has not so far received a satisfactory definition, which would enable us by applying it in every particular case to find out whether a certain linguistic unit was a sentence or not.

Under this heading wo will treat such formations as apart from, with reference to, as soon as, so long as, etc., which quite obviously are phrases rather than words, and which quite definitely perform the same function in a sentence as prepositions and conjunctions respectively.