Hearing or speaking a foreign language is read as an unfamiliar part of yourself or of life trying to communicate. Understanding it traditionally stands for insight; not understanding it, for confusion.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.