What does "they are walking" mean in English for Spanish?

In English for Spanish, "they are walking" means:

ellos están caminando

Listen to "they are walking": (If you have an HTML5 enabled browser, you can listen to the native audio below)

This is a phrase that is used in the GamesForLanguage English for Spanish Language Game in the following scenes:

• English for Spanish 3, Level 2, Scene 7
• English for Spanish 4, Level 2, Scene 2