/f/

Gently place your upper front teeth on your lower lip - not biting down hard, just resting lightly. Now push a steady stream of air through the narrow gap between your teeth and lip. You should hear a soft, continuous hissing sound, like air escaping from a tire.

This is a voiceless sound, so your vocal cords should stay silent. If you place your hand on your throat while making the sound, you shouldn't feel any vibration. The friction between your teeth and lip creates the sound, not your voice.

Since /f/ exists in English, native speakers rarely struggle with this sound. However, some points to watch:

• Adding voice: If you accidentally engage your vocal cords, you'll produce /v/ instead ("van" instead of "fan"). Keep your throat relaxed and silent.
• Weak contact: If your teeth barely touch your lip, the sound comes out too soft and breathy. Make sure there's light but definite contact.
• Using both lips: Don't press your lips together like you're making a /p/ or /b/. Only your lower lip should be involved, touching your upper teeth.

Try the "paper test": hold a small piece of paper in front of your mouth and say "fun." The paper should flutter from the air stream. If it doesn't move, you're not releasing enough air through the teeth-lip contact.

For words ending in /f/ like "off" or "leaf," remember to clip the vowel short. English vowels are naturally shorter before voiceless sounds like /f/ compared to their voiced counterpart /v/.