Questions & Answers about Nie było mnie wczoraj w domu.
Why is it Nie było mnie instead of just saying Nie byłem or Nie byłam?
While you technically can say Nie byłem w domu (if you're a man) or Nie byłam w domu (if you're a woman), Polish strongly prefers the impersonal phrase nie było mnie to express absence. It translates literally to "there was no me". This is the most natural and standard way native speakers say they weren't somewhere.
Why do we use the word mnie here instead of ja?
Mnie is the genitive case of ja (I). In Polish, when you state that someone or something is not present or doesn't exist, the person or thing that is missing must take the genitive case. Because you are expressing your own absence, the nominative ja changes to the genitive mnie.
Why is the verb in the neuter form (było) even if the speaker is a man or a woman?
Because this is an impersonal sentence. By putting the missing person into the genitive case (mnie), you've removed the grammatical subject of the sentence. Whenever a Polish sentence lacks a subject in the nominative case, the verb automatically defaults to the third-person neuter singular form—which in the past tense is było.
Can I use this exact same structure to say someone else wasn't at home?