Grammatical classification of the subject
From the point of view of its grammatical value the subject may be either notional or formal.
The notional subject denotes or (if expressed by a pronoun) points out a person or a non-person.
The formal subject neither denotes nor points out any person or non-person and is only a structural element of the sentence filling the position of the subject. Thus a formal subject functions only as a position-filler. In English there are two such position-fillers: it and there.
The notional subject
The notional subject denotes or points out a person or non-person, that is, various kinds of concrete things, substances, abstract notions or happening.
Persons:
I know all about it.
Non-persons, including animals, whose name may be substituted by itor they.
Look at the cat. It is very small.
(it): Personal (cm. non-perons). The demonstrative “it” – when it points out some person or thing expressed by a predicative noun, or refers to the thought contained in a preceding statement, thus having a demonstrative meaning: It is John.
The formal subject
The formal subject it
The formal subject expressed by it is found in two patterns of sentences: those with impersonal it and those with introductory it. And Emphatic.
1. The formal subject it is impersonal when it is used in sentences describing various states of nature, things in general, characteristics of the environment, or denoting time, distance, other measurements.
It’s cold today. - Сегодня холодно.
Sentences with impersonal it are usually rendered in Russian by means of impersonal (subjectless) sentences.
2. The formal subject it is introductory (anticipatory) if it introduces thenotional subject expressed by an infinitive, a gerund, an infinitive/gerundial phrase, a predicative complex, or a clause. The sentence thus contains two subjects: the formal (introductory) subject it and the notional subject, which follows the predicate.
It was no good coming there again.
Sentences with introductory it can be transformed into sentences with the notional subject in its usual position before the predicate.
The difference between the two structural types lies in that the pattern with the introductory subject accentuates the idea expressed by the notional subject, whereas the pattern without it accentuates the idea expressed in the predicate.
Sentences with introductory it must be distinguished from certain patterns of sentences with impersonal it:
a) sentences with the predicate expressed by the verbs to seem, to appear, to happen, to turn out followed by a clause, as in It seemed that he didn’t know the place.
In these sentences describing a certain state of affairs it is impersonal, not introductory and the clause is a predicative one. So it cannot fill the position of the subject:
It seemed that he did not know the place —/—> That he did not know the place seemed. (Transformation is impossible)
b) sentences with predicative adjectives preceded by too and followed by an infinitive as in It was too late to start.
Here it is used in sentences describing time, etc. and is therefore impersonal. The infinitive is an adverbial of consequence, not the subject, and so cannot be placed before the predicate:
It was too late to start —/—> To start was too late.
c) sentences with the predicative expressed by the noun time followed by an infinitive, as in It was high time to take their departure.
In such sentences it is also impersonal, the infinitives being attributes to the noun time. These sentences cannot therefore undergo the transformation which is possible in the case of sentences with introductory it:
It was time to take their departure ―/→ To take their departure was time.
Thus, the subject it may be personal, impersonal, and introductory. In the latter two cases it is formal.
The emphatic “it”is used for emphasis, to give explanations or to make a contrast with a previous statement: All the Redgrave family are gifted actors. But it is Vanessa who made the greatest impact in the world of feature films.Itwas at the station where he met me at five o’clock.
The formal subject there
Sentences with a notional subject introduced by there express the existence or coming into existence of a person or non-person denoted by the subject. Such sentences may be called existential sentences or sentences of presentation. They are employed where the subject presents some new idea or the most important piece of information.
The notional subject introduced by there is expressed:
1. By any noun or by a noun phrase denoting an inseparable unit or an indefinite amount of something. There were a lot of people in the street.
As the notional subject usually introduces a new idea, the noun expressing it is generally used with the indefinite article.
2. By some noun-pronouns: a) indefinite. Is there anybody there?
b) negative. There was nobody in.
c) universal (only some of them). There were all of them on the bank.
The pronouns of these three classes are the most frequent in existential sentences. The ones that follow are very seldom used: d) detaching. There was the other to be asked.
e) demonstrative. There is this which is to be settled.
3. By a gerund or a gerundial phrase. There was no talking that evening.
4. By a clause. First, there is what we might call a pattern.
The predicate in such sentences is generally a simple verbal predicate expressed by the verbs to be, to appear, to live, to come, to go, or some other similar verbs.
Once upon a time there lived a king.
Occasionally the predicate may be a compound verbal modal predicate or a predicate of double orientation. In both cases their second parts are expressed by the verb to be, or one of the others mentioned above.
a) There must be something wrong with him.
b) There seemed to be only two people in the room.
Negative sentences with introductory there are formed in the usual way for the verbs which are their predicates, that is, by means of appropriate auxiliaries for all the verbs but to be. In the latter case two negative constructions are possible:
a) either with the negative pronoun no, as in: There was no sign of him in the hall.
b) or with the negation not, often followed by the indefinite pronoun any, or without it, as in: There isn’t a cloud in the sky.
The sentence is also negative if the subject itself is a negative pronoun:
There was nobody in.
Speaking about the structural types of the subject, we can single out the following types:
1. simple – expressed by a single word form: The fog was thinning.
2. phrasal – expressed by a phrase: Two and three is five.
3. complex – expressed by a predicative complex: It’s easy for you to talk so. (a for-to-infinitive complex)
Your knowing a thing is nothing unless another knows that you know it. (a gerundial complex)
4. clausal – expressed by a subject clause: What I need is a piece of good advice.