Speak Mandarin out loud
Say the word into your microphone and see how close you got: measured against the course's own recordings, and checked by a machine listener, tones included.
This feature is experimental. Scores are a rough guide, not a grade - microphones, rooms and accents all move the numbers. If it says you are miles off but a patient native speaker would understand you, believe the native speaker.
Say this word
的
de
of, possessive and modifier particle
Your recording is scored and discarded - it is never stored.