Learn Spanish (Latin America): El actor y la actriz bailan.

In Spanish, not all feminine words end in -a. The masculine word is actor, and its feminine form is actriz. This is similar to English, where we change actor to actress instead of just adding a standard ending. You can tell it is feminine because it is paired with the feminine article la.

Why is the verb bailan used here instead of baila?

Bailan is the they form of the verb bailar (to dance). Because the subject of the sentence is two people (el actor y la actriz), you treat them as they (ellos). For regular -ar verbs, the they form always ends in -an.

If I wanted to replace the actor and the actress with a pronoun, would I use ellos or ellas?

You would use ellos. In Spanish, when you have a mixed group of males and females, you always use the masculine plural pronoun ellos for the whole group.

How do I pronounce the z in actriz in Latin American Spanish?

In Latin America, the letter z always sounds exactly like an English s. So actriz sounds like ahk-TREES. In Spain, it is often pronounced with a th sound, but you do not need to do that for Latin American Spanish.