How to pronounce ‘th’ in English? The tongue tip touches gently behind the top front teeth. The air comes out in between the tongue tip and the top teeth. For unvoiced ‘th’, like in the words ‘think’ and ‘thank’ there is no voice. For voiced ‘th’ like in the words ‘that’ and ‘this’ there is vibration from the voicebox.

To pronounce the voiced “th” as in the word “this” we need to turn the voice on. Put your hand on your throat, and simple say “ah”. You can feel the throat vibrate.

The voiced TH /ð/ sound is produced by placing the tip of the tongue between the upper and lower front teeth, similar to the unvoiced TH /θ/ sound, but with the vocal cords vibrating. This creates a voiced sound that is similar to the "th" sound in "the" or "that".

ESL: The 'voiced th' /ð/ and 'unvoiced th' /θ/ sounds are the only pair of English sounds that share a single, common spelling. To pronounce the sounds, the tip of the tongue is placed behind the top front teeth. The friction occurs between the tip of the tongue and the top front teeth.