1. A grammatical subject that does not refer to a specific person or entity, often used with impersonal verbs or constructions where the subject is indefinite or represents a general condition
In the sentence 'It is raining,' 'it' is an impersonal subject.
Na frase 'Está chovendo', 'está' é um sujeito impessoal.
2. A construction in which the subject is a dummy pronoun or an abstract notion rather than a concrete agent performing an action
In 'There are many reasons to celebrate,' 'there' functions as an impersonal subject.
Em 'Há muitas razões para celebrar', 'há' funciona como um sujeito impessoal.