Конструктивный синтаксис (структурный)

The category of person and number
Traditionally the category of number is treated as the correlation of the plural and the singular, and the category of person as the correlation of three deictic functions reflecting the relations of the reference to the participants of speech communication: the first person is the speaker, the second – the addressee and the third – the object of speech.
Note: the category of deixis (deictic)? implies the information which can be adjectivally understood only when the components of the speech situation are known. There are 3 main components of a speech situation: time, place and the participants of a speech situation (the deictic expression of time – It happened an hour ago; the deictic expression of place – it happened there/here; the deictic expression of participants of a speech situation – he/she/I came to John place yesterday)

But in the system of the verb in English these two categories are so closely interconnected both semantically and formally that they are often referred as one single category the category of person and number.

In the meaning of the subject the expression of number semantic is blended with the expression of person semantic. (in the paradigm of personal pronouns the following six members are distinguished by person and number characteristic combine: I – the first person singular, we - the first person plural, you the second person plural or singular, she-he-it the third person singular, they - the third person plural). Formally the categories of person and number are also fused (слились). Being expressed by one and the same verbal form (he speaks).
In modern English all verbs can be divided according to the expression of this categories into three groups:
1) Modal verbs distinguish no person number forms at all.
2) The verb to be on the contrary has preserved more person number forms than any other verbs in modern English (am, is, are, was, were).
3) The bulk verbs have a marked form in English only for the third person singular in present tense indicative mood. Thus the category of person and number in English is asymmetrical realized in the present indicative mood by the opposition of two forms: the marked member is the third person singular and the unmarked member embraces all the other person and number forms.
The deficient person number paradigm of the verb in English makes syntagmatic relation between the verbal lexeme and the lexeme denoted the subject obligatory for the expressed of this category (неполноценная парадигма окончаний лица и числа глагола в англ языке подразумевает синтагматические отношения лексемы глагола и лексемы подлежащего). I speak/ you speak/ they speak/
Deficient as it is the system of person and number forms of the verbs in English place an important semantic role in contexts in which the forms of the noun do not distinguish the category of number (the family (семья ) was gathered round the table; the family (члены семьи) were gathered round the table).
Uncountable nouns can distinguish the capacity to be used only in the singular or only in the plural by means of the corresponding verbal forms (police, clothes).
The category of person and number can be neutralized in colloquial speech (here is your keys).