Give P, T, K a Little Puff of Air

In English, when P, T, or K starts a stressed syllable, it comes with a small burst of air — try holding a tissue in front of your mouth while saying 'pin,' and you'll see it flutter. Vietnamese doesn't require this extra puff, so without it, words like 'pin,' 'top,' and 'cat' can sound closer to 'bin,' 'dop,' or 'gat' to American ears, even though you meant the voiceless sound the whole time. The good news: the fix is simple and physical, not about retraining your whole mouth. Try 'pin' versus 'bin' with a tissue held an inch from your lips — 'pin' should make it move, 'bin' shouldn't. Practice with 'top,' 'car,' and 'pen,' exaggerating the puff each time. Two minutes with that tissue trick will make the difference obvious immediately. Once you can feel it working, that little extra breath becomes an easy habit to keep.