Voiced "TH" (as in "this" or "that"):
* Tongue position: The tip of your tongue is placed right behind your front teeth, with the sides of your tongue touching your upper teeth.
* Airflow: Air is forced through a narrow channel between your tongue and teeth, creating a friction sound.
* Vocal cords: Your vocal cords vibrate, creating the "voiced" aspect of the sound.
"D":
* Tongue position: The tip of your tongue touches the roof of your mouth just behind your teeth.
* Airflow: Air is stopped by your tongue, then released quickly, creating a stop sound.
* Vocal cords: Your vocal cords vibrate, making it a voiced sound.
Key differences:
* Tongue placement: The tip of your tongue is placed further back for "TH" than for "D".
* Airflow: "TH" involves a continuous airflow through a narrow channel, while "D" involves a stop-and-release of air.
* Sound quality: "TH" has a friction sound, while "D" has a stop sound.
Example: Say "this" and then "dis." You'll notice the difference in the way your tongue moves and the sound that is produced.