Every language trains the ear of those who grow up with it. Brazilian Portuguese has seven oral vowels, while American English has between eleven and fifteen, depending on how you count. This means there are English sounds your ear was simply never calibrated for — and the brain does what it always does with something unfamiliar: it files it under the closest sound it already knows.

It is not a lack of effort or talent. It is perceptual. And the good news is that perception can be trained at any age.

1. The short i in ship

The most famous pair: ship and sheep. Portuguese has only one i, the long, tense one in “vi”. English also has a short, relaxed i, produced with the tongue lower and the mouth slightly more open.

The mistake can be costly in real situations: I need a sheet of paper and its short-i counterpart are two very different sentences to say in a meeting.

2. The th in think and this

These are two distinct sounds, both absent from Portuguese, and both produced with the tip of the tongue between the teeth. Portuguese speakers tend to replace them with t, d, f or s — and then think becomes sink, and they becomes day.

The fix is mechanical before it is auditory: the tongue has to show. Students find it strange, and it is — for a few days.

3. The aspirated h in house

In Portuguese, a written h is silent. In English it is a real breath. When that breath is missing, heat sounds like eat. And when it shows up where it should not — a common overcorrection habit — hour gains an h that does not exist.

4. The retroflex r in red

The American English r does not touch the roof of the mouth. The tongue curls back without touching anything. The strong Portuguese r, produced in the throat, changes the word completely: red pronounced with a Brazilian r sounds closer to head to an American ear.

5. Final consonants that do not get a vowel

This is the most persistent of all. Portuguese rarely ends a syllable in a consonant, so we add a support vowel without noticing: hot dog becomes hotchy dogui, and Facebook gets an i at the end.

In an isolated word, this goes unnoticed. In a full sentence, each extra vowel adds a syllable, the rhythm falls apart and the listener loses the thread.

How to really train this

Listening to a lot of English helps, but it is not enough. The ear keeps filing the new sound under the old category until someone points out the difference explicitly. What works is practicing with minimal pairs — two words that differ by a single sound — listening, producing and receiving immediate correction.

This is exactly the kind of work that pays off more in a one-to-one lesson than in a group: no one can correct the tongue position of fifteen people at the same time.