Learn Spanish (Latin America): ¿Están construyendo un hospital nuevo?

The verb is construir (to build). Normally, verbs ending in -ir take the ending -iendo to show an action in progress. However, adding -iendo here would create construiendo, putting an unstressed 'i' between two other vowels. To make pronunciation easier, Spanish changes that 'i' to a 'y', giving us construyendo. You will see this same spelling change in other verbs, like leer (to read) becoming leyendo.

Where is the word for 'they' in this sentence?

In Spanish, the verb form están already tells us the subject is 'they' (or 'you all'). Because están combined with construyendo clearly means 'they are building', you can leave out the pronoun ellos (they). Spanish speakers usually drop the subject pronoun unless they need it for emphasis or to clear up confusion.

Why is nuevo placed after hospital?

In Spanish, descriptive adjectives like nuevo (new) almost always come right after the noun they describe. So, instead of saying 'a new hospital' like we do in English, you say un hospital nuevo (literally 'a hospital new').

Is hospital pronounced the same way it is in English?

The spelling is exactly the same, but the pronunciation is different. The letter 'h' is always silent in Spanish, so you start straight with the 'o' sound. Additionally, the spoken stress falls on the very last syllable, making it sound roughly like 'os-pee-TAL'.