Learn Spanish (Latin America): ¿Qué tan cara es la motosierra eléctrica?

Cómo usually asks about the manner or method ("in what way"), like ¿Cómo funciona? (How does it work?). When you want to ask about the degree or extent of an adjective or adverb—like "how expensive," "how far," or "how difficult"—Latin American Spanish uses qué tan followed by that adjective or adverb. So, "how expensive" translates to qué tan cara.

Does the adjective after qué tan always have to match the noun it describes?

Yes! Even though cara is right next to qué tan, it still describes la motosierra (a feminine, singular noun). That's why it is cara and not caro. If you were asking about a car (el auto), you would say ¿Qué tan caro es el auto?

Why do we use es instead of está for asking if it's expensive, since prices can change?

We use ser (es) because being expensive is treated as a characteristic of this specific chainsaw. While specific price tags can fluctuate, categorizing an item as "cheap" or "expensive" as a general trait is done with ser (ser caro or ser barato). You would typically use estar for prices only when asking the current rate of something that fluctuates daily, using the formula estar a (like ¿A cuánto está el dólar?).