Breakdown of Trzeba przeczytać tę książkę zamiast gazety.
książka
book
ta
this (f)
gazeta
newspaper
przeczytać
to read (perfective)
Questions & Answers about Trzeba przeczytać tę książkę zamiast gazety.
Why does the word for newspaper change to gazety here?
The word zamiast (instead of) is a preposition that requires the noun following it to take the Genitive case. Because gazeta is a feminine noun ending in -a, it changes to -y in the Genitive, giving us zamiast gazety.
Who is the subject of trzeba?
There isn't one! Trzeba is an impersonal word meaning 'it is necessary to' or 'one must.' You don't conjugate it for specific people (like I, you, or they). You simply follow it with a verb in its dictionary form (the infinitive), which in this sentence is przeczytać.
Could I use czytać instead of przeczytać in this sentence?
You could, but it changes the meaning slightly. Przeczytać is a perfective verb, which focuses on completing the action—reading the book from start to finish. If you used the imperfective czytać, it would just mean you need to spend time reading the book, without necessarily finishing it.
Why is it tę książkę and not tą książkę?