Learn Spanish (Latin America): ¿Puedes comprar el helado que nos gusta?

In Spanish, the verb gustar works differently than the English verb "to like". It actually translates closer to "to be pleasing". So, instead of saying "we like the ice cream", the Spanish sentence is structured as "the ice cream is pleasing to us". Because el helado (the ice cream) is the subject doing the pleasing, and it is singular, we use the singular verb form gusta.

What does the word nos do in this sentence?

Nos is a pronoun that means "to us". It pairs with gusta to show exactly who the ice cream is pleasing to. Whenever you want to say "we like" a single thing or an action, you will use the combination nos gusta.

Why are there two verbs back-to-back (puedes comprar)?

When you combine two verbs to express a single idea, only the first verb changes to match the person doing the action. Puedes is conjugated to mean "you can". The second verb, comprar (to buy), stays in its original, unchanged dictionary form (the infinitive) because it just finishes the idea of the first verb.

I thought qué meant "what", but here it translates to "that". Why?