With any conversation, it is important that discussants are speaking the same language both literally and in the sense that all member of the conversation should be on the same page.
As an undergraduate you are not technically required to be able to speak the local languages of your fieldwork. However, when considering language preparation, you should remember that things are often lost in translation. Speaking the language of the people you are working with helps not only in clarity of communication, but in more effectively and genuinely integrating yourself into a community.
Here, we show you a video of how students and faculty have experienced language in the field.