th voiced/un

Core Rule

TH voicing has two sounds: voiceless /θ/ and voiced /ð/. The key is vocal-fold vibration. Voiceless often appears in content words; voiced is frequent in function words.

Articulation Guide

Place the tongue tip lightly between the teeth. For /θ/, push air with no vibration. For /ð/, keep airflow and add voicing; feel a buzz in the throat.

Examples

/θ/: think, bath, author. /ð/: this, those, weather. jeans is /dʒiːnz/; the letter j is not TH, a common spelling trap.

Pitfalls

TH is not /t/+/h/. Avoid replacing /ð/ with /z/ or /d/, and /θ/ with /s/. Position does not change the rule; check phonemic cues.