Breakdown of Gdy przeczytała list, nagle zapłakała.
list
letter
przeczytać
to read (perfective)
nagle
suddenly
gdy
when (conjunction, = kiedy, more written)
Questions & Answers about Gdy przeczytała list, nagle zapłakała.
What exactly does the prefix za- add to the verb płakać in this sentence?
It marks the sudden beginning of the action. While the base imperfective verb płakać means to cry or to be crying, adding the prefix za- creates the perfective verb zapłakać, which means to burst into tears or to suddenly start crying.
Why use the perfective verb przeczytała instead of the imperfective czytała?
Using the perfective przeczytała shows that she completely finished reading the letter before the next action happened. If the sentence used the imperfective czytała, it would mean she burst into tears while she was still in the middle of reading it.
Is there any difference between using gdy and kiedy at the start of this sentence?
They mean the exact same thing here. Both translate to when and are used to connect events in time. Gdy is just slightly more literary and very common in written Polish, while kiedy is widely used in both everyday speech and writing.
Why doesn't the word list have a special case ending, given that it is the direct object of the reading action?
It is actually in the accusative case, which is the standard case for a direct object. However, because list is a masculine inanimate noun, its accusative form is identical to its basic dictionary form (the nominative). Therefore, its ending does not change.