The subject of the sentence is the term with which the verb agrees in number and person. When it appears in prayer, it is called determinate, but when it is implied (hidden), it is called indeterminate.
Grammatically, it is very simple to classify the subject as indeterminate. This classification occurs in two situations:
Third person plural verb without explicit subject. Look:
They went through my drawer.
Intransitive, linking or indirect transitive verbs in the third person singular, accompanied by the pronoun if, which, in this case, will be an index of indeterminacy of the subject. Watch:
Teachers are needed.
People live better in the countryside.
Although most are only concerned with the issue of classification of the indeterminate subject, there is a very important aspect, mainly for interpretation, the semantics.
Semantics studies the meaning of words, phonemes, sentences. However, it does not only study the word itself, but is concerned with the relationship it establishes with each other and with the context.
Analyzing the indeterminate subject and considering the semantic issues (of meanings), it is possible to perceive the following aspects:
The subject is indeterminate because it is really unknown who performed the action.
The subject is indeterminate because, for some reason, it cannot be presented or appear.
The aspects mentioned above are the most common in subject indeterminacy. However, there are others that should be considered:
The indeterminate subject is used to generate suspense.
Friend, yesterday at college, they asked about you.
The indeterminate subject is used when someone knows the author of the action, but does not want to point him out because he wants him to present himself. In that case, it's important to have a context. Look:
The daughter soiled the sofa and the mother says:
"They soiled my sofa."
(By using the subject's indeterminacy, the mother expects the daughter to surrender).
The indeterminate subject is used when the action, which was committed in secret, was witnessed by someone who, although not wanting to tell the author, wants to tell the fact. In this case, the context is also important. Analysis:
In between, there is a fight in the courtyard. Someone comes to the director and says:
"They hit André!"
As you could see, semantic aspects are very important when the intention is to understand the text. Therefore, they must not be forgotten.
By Mayra Pavan
Graduated in Letters
Source: Brazil School - https://brasilescola.uol.com.br/gramatica/sujeito-indeterminado-intencao-discurso.htm
