Breakdown of Kiedy pada, trzeba wbiec do budynku.
do
to
budynek
building
kiedy
when
trzeba
one must, it is necessary (+ infinitive)
Questions & Answers about Kiedy pada, trzeba wbiec do budynku.
Why use wbiec here instead of just biec?
The base verb biec means "to run" as an ongoing action. By adding the prefix w-, we create the perfective verb wbiec, which specifically means "to run into" or "to enter by running". This fits perfectly because getting out of the rain is a completed, one-time action of entering.
Why do we need the word do before budynku? Doesn't the w- prefix in wbiec already mean "into"?
The w- prefix does carry the meaning of "into", but Polish grammar still requires a preposition to connect this type of motion verb to its destination. Verbs for entering with the w- prefix pair with the preposition do plus the Genitive case. That is why the basic noun budynek (building) changes to its Genitive form, budynku.
Why is there no word for "you" before trzeba?
The word trzeba is an impersonal expression meaning "one must" or "it is necessary". It never takes a normal subject pronoun like "ja" or "ty". When it is translated as "you have to", it means "you" in a general sense (meaning anyone caught in the rain). It is always followed by an infinitive verb, which is why the unconjugated form wbiec comes right after it.
I learned that pada means "falls". Why does it mean "it rains" in this sentence?