Учебно-методическое пособие для студентов математического факультета специальности 1-020501 «Информатика. Иностранный язык (английский)»

«elementary sentence»
is to be recognized; this is a sentence all the positions of 
which are obligatory. In other words, this is a sentence which, besides the 
principal parts, includes only 
complementive modifiers
; as for 
supplementive 
modifiers
, they find no place in this type of predicative construction. 
After that the types of expansion should be determined which do not 
violate the syntactic status of the simple sentence, i.e. do not change the simple 
sentence into a composite one. Taking into consideration the strict 
monopredicative character of the simple sentence as its basic identification 
predicative feature, we infer that such expansions should not complicate the 
predicative line of the sentence by any additional predicative positions. 
Finally, bearing in mind that the general identification of obligatory 
syntactic positions affects not only the principal parts of the sentence but is 
extended to the complementive secondary parts, we define the 
unexpanded 
simple sentence
 
as a monopredicative sentence formed only by obligatory 
notional parts. The 
expanded simple sentence 
will, accordingly, be defined as a 
monopredicative sentence which includes, besides the obligatory parts, also 
some optional parts, i.e. some supplementive modifiers which do not constitute a 
predicative enlargement of the sentence. 
The subject-group and the predicate-group of the sentence are its two 
constitutive «members», or, to choose a somewhat more specific term, its 
«axes» (in the Russian grammatical tradition – «составы предложения»). 
According as both members are present in the composition of the sentence or 
only one of them, sentences are classed into 
«two-member»
and 
«one-
member»
ones. 
All simple sentences of English should be divided into