Brazilian Portuguese Grammar

*Índice de indeterminação do sujeito se* Se as a marker of the indefinite subject
This is a another typical structure in Portuguese: Pronoun se is attached to verbs in the 3rd person singular; this is followed by a prepositional phrase, which is the verb complement (indirect object). Se is called índice de indeterminação do sujeito. This is not a kind of passive voice. Prepositional verb + se .....preposition + complement
Portuguese	Closest English equivalent
Precisa-se de funcionários.	One needs employees.
Precisou-se de funcionários.	One needed employees.
Precisava-se de funcionários.	One needed employees.
Precisar-se-á de funcionários.	One will need employees.
Precisar-se-ia de funcionários.	One would need employees.
Verb precisar is a prepositional verb (precisar de), so it meets the requirement to build sentences with índice de indeterminação do sujeito se.

Se and pronominal verbs

Se is also used with pronominal verbs, of which it is a component. It appears in the infinitive form, and also in the 3rd person singular and plural. Pronominal verbs must be learned by heart. Pronoun se can also be used with reflexive verbs, and the conjugation pattern below also applies to them.

Only unstressed object pronouns (me, te, se, o, a, lhe, nos, vos, os, as, lhes) can be placed in the proclitic, enclitic or mesoclitic position in relation to the verb. Refer to the page Object pronouns & placement rules to understand or review these concepts.