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The direct parallel of the example from Finnish does not exist in English dialects know to me.  Which does not stand for much, I'm not even a native speaker.

There are some basic uses of "it" which do refer to a person and which are available rather uniformly across dialects of English.

1) Person (or animal) whose (binary) sex is unknown or disregarded.  Example: *"Who was it that told you that?"*

2) Person whose gender is non-binary.  (The person may have opted into the pronoun.)

3) Jocular or derogatory use.  (The sentence will often contain additional depersonalizing lexical items, creating a tension between the subject being clearly a person, but the speaker treating them as a non-person.  Such usage would be studied under pragmatics, not semantics, it doesn't constitute an independent meaning of the word "it".)

4) Ante-referential use.  *"John is a postman but he hates to be it."*  (In such a sentence, we could perhaps argue whether "it" refers to a "postman" or to John's "postmanship", which could further be analyzed as a countable person and an uncountable abstraction, respectively.)

With enough context twisting, almost every word can be made to refer to almost anything, and "it" is an especially flexible referent due to its native use to refer to any abstractions - abstractions are included in non-persons.

Some usages of "it" may look superficially like they are referring to a person, but aren't. *"It is she who carries my baby."*  Here, "it" is a part of a set phrase "it is/was ... who/that ...", the phrase is used for emphasis, and that phrase is compatible with any grammatical person and any referent, including plural referents.