Breakdown of Mój stary komputer jest trwały, natomiast ten nowy jest wydajniejszy.
być
to be
ten
this (m)
nowy
new
stary
old
Questions & Answers about Mój stary komputer jest trwały, natomiast ten nowy jest wydajniejszy.
Why use natomiast here instead of just ale (but) or jednak (however)?
Natomiast translates best to "whereas" or "while". It's used to contrast two different things by comparing their distinct qualities—here, the durability of the old computer versus the efficiency of the new one. Ale or jednak would sound a bit too adversarial, as if being efficient contradicts being durable.
How does the word wydajniejszy (more efficient) get its ending?
This is the comparative form of the adjective wydajny (efficient). For adjectives ending in -ny, the comparative ending for masculine nouns is usually -niejszy. Therefore, wydajny becomes wydajniejszy.
Why is the word komputer missing in the second half of the sentence (ten nowy)?
Just like in English where we can say "this new one", Polish allows you to drop the noun entirely if it's obvious from the context. The phrase ten nowy simply takes the same masculine form as the implied noun komputer.