Smoo[th] — Choose the word that has the same consonant sound as the one in bracket

Analyze the question: "Smooth" ends with the voiced "th" sound, /ð/ (as in this, that, then). We need the option whose "th" is also /ð/.

Concept: English has two "th" sounds:

• Voiceless /θ/ as in think, bath, worth. Your vocal cords do not vibrate.
• Voiced /ð/ as in smooth, this, brother. Your vocal cords vibrate. Put your fingers on your throat and you will feel a buzz.

Step-by-step check of the options:

• A. worth: the "th" is /θ/ (voiceless). ✗
• B. dress: there is no "th" sound at all, only /s/. ✗
• C. brother /ˈbrʌðə/: the "th" is /ð/ (voiced). ✓
• D. wealthy /ˈwelθi/: the "th" is /θ/ (voiceless). ✗

Answer: The "th" in brother matches the voiced /ð/ in smooth.

Tip: Say the word and feel your throat. If it buzzes, the sound is voiced /ð/. Common voiced "th" words include this, that, them, mother, father, brother, breathe, smooth. Voiceless ones include think, thin, path, worth, wealth.