A nosotros ___gusta bailar

A nosotros nos gusta bailar.

The missing word in the sentence is "nos." The correct sentence would be "A nosotros nos gusta bailar."

To understand why "nos" is necessary in this sentence, it's important to know a bit about Spanish grammar. In Spanish, the verb "gustar" (to like) is a special verb that works differently than in English. In Spanish, the thing that is liked becomes the subject of the sentence, while the person doing the liking is expressed as an indirect object.

In this case, "bailar" (to dance) is the thing that is liked, so it becomes the subject of the sentence. "Nosotros" (we) is the indirect object, indicating that it is "us" who likes to dance. To make this clear, we need to include the pronoun "nos" before the verb "gusta."

So, to say "We like to dance" in Spanish, we say "A nosotros nos gusta bailar." The "a nosotros" part emphasizes that it is specifically "us" who likes to dance.