/θ/
The 'th' in 'think', 'thank', 'three'
Both Vietnamese and Mandarin lack this sound. Many students replace it with /t/ or /s/, saying "tink" or "sink" instead of "think".
Trick: put the tip of your tongue lightly between your teeth. Blow air gently. That's /θ/. It feels strange — that means you're doing it right.
/v/
The 'v' in 'very', 'voice', 'love'
Mandarin speakers often replace /v/ with /w/, saying "wery" instead of "very". Vietnamese has a /v/ sound but it can be softer than English /v/.
Trick: bite your bottom lip gently with your top teeth. Then make a buzzing sound. That's /v/.
-ed
Final consonants — the most common loss of marks
In Vietnamese, final consonants exist but are "unreleased" — you don't fully pronounce them. In Mandarin, syllables almost never end in consonants like /k/, /p/, /t/, /d/, /s/. So "walked" becomes "walk-uh" or "walk", and "helped" becomes "help".
Trick: pretend every -ed verb has a tiny 't' sound at the end. walked → walk-T · helped → help-T · stopped → stopp-T
/r/ /l/
'r' and 'l' — different mouths
Mandarin speakers sometimes mix 'r' and 'l', saying "lice" for "rice". The mouth shapes are very different. For 'r', curl the tongue back without touching anything. For 'l', press the tongue tip on the ridge behind the top teeth.
Practise: red lorry, yellow lorry. (Slowly. Then faster.)