/θ/ vs /f/

/θ/ uses the tongue; /f/ uses the lower lip against upper teeth. Common substitution.

Minimal pairs to practice

• thin vs fin
• three vs free
• thought vs fought
• death vs deaf
• thirst vs first
• thread vs Fred

Record each pair below. The analyzer listens for which side of the pair you actually produced and tracks your discrimination rate over time — visible as a chip on your Pronunciation Map.