You do that by changing the word "want." Again, if you wanted to say, "I wanted soup yesterday," you do that by converting the word "want" into "wanted." It's a past tense.
Hay que hacerlo cambiando la palabra "querer". Y si quisiera decir: "ayer quería sopa", lo haría transformando la palabra "querer" en "quería". Es un tiempo en pasado.