Breakdown of A veces olvido las zapatillas; quisiera unas nuevas, por favor.
las
the (feminine plural)
unas
some (feminine)
nuevo
new
querer
to want
Questions & Answers about A veces olvido las zapatillas; quisiera unas nuevas, por favor.
Why use quisiera here instead of quiero or me gustaría?
Quisiera is the imperfect subjunctive form of querer (to want). Even though it is technically a past tense, it is widely used as a polite way to say "I would like" in the present. It sounds softer and less demanding than quiero (I want). You could also use me gustaría, but quisiera is incredibly common and natural for direct requests or placing orders.
Why does the sentence say unas nuevas instead of unas zapatillas nuevas?
In Spanish, you can easily drop a noun if it is already obvious from the context. Because we just mentioned las zapatillas, we can skip repeating it and just use the article unas (some) followed by the adjective nuevas (new) to mean "some new ones." Notice that both words must still match the feminine, plural form of the hidden noun (zapatillas).
I previously learned "to forget" as olvidarse de. Why is it just olvido here without me or de?
Both olvidar and olvidarse de mean "to forget," and you can use either one here! Olvidar is used with a direct object right after it (olvido las zapatillas). Olvidarse requires a reflexive pronoun and the preposition de (me olvido de las zapatillas). They mean the same thing, though olvidarse de is often a bit more common in everyday spoken Spanish.