Because your native language is Portuguese, you naturally will have difficulty pronouncing several American English sounds. You may notice that some are harder to learn than others. Here are a few sounds that you are most likely having difficulty pronouncing.
1. The “z” sound is often pronounced like “s” This sound may be very challenging for you because you naturally pronounce “z” in Portuguese like the American English “s” sound.
In American English we form the "s" and "z" sounds the same; place the tip of your tongue behind your top front teeth, but not touching them. Prolong the sound by making only very light contact with your tongue and roof of your mouth.
The difference between the sounds is in what we call “voicing.”We use our voice to say “z” but don’t for “s.”The tricky part is that most of the time, the “z” sound in English is represented with the letter “s.”
The word “was” may sound like “wuss.” The word “busy” may sound like “bissy.”
2. The voiced “th” sound is usually pronounced like “d” Because you don't have the "th" sound in Portuguese, you may find that this sound is difficult to learn initially. To form this sound in American English you need to stick out your tongue in between your teeth. You should feel your top front teeth resting very gently on it. Keep your tongue and teeth in contact and push out your voice as you prolong the sound. You use your voice to say this sound, which means that if you place your hand on your throat when you say it, you should feel your vocal cords vibrate. You will also hear your voice.
The word “the” may sound like “duh.” The word “that” may sound like “dat.”
3. The "p" sound is often pronounced like "b" The "p" and "b" sounds are formed in exactly the same way in American English, except one uses your voice and the other doesn't.
To form the "p" sound, place your lips together, hold your breath, and then force the air out of your mouth in a little explosion. This sound does not use your voice, which means that you should only hear a puff of air when you say it. If you place your hand on your throat when you say this sound, you should not feel any vibration.
For the "b" sound, you will place your lips together in the same way you did for "p," and you hold your breath. This time, however, when you force the sound out, you will use your voice. This means that if you place your hand on your throat when you say "b," you should feel a vibration.
The word "pay" will sound like "bay" The word "pad" will sound like "bad"
"z" sound "s" sound
Smile and rest the tip of your tongue very lightly behind your teeth. Use your voice when you say this sound. Remember that it needs to be prolonged.
The "z" and "s" sounds are formed exactly the same way with one exception; you use your voice when saying "z," but not with "s." If you use your voice for "s" you will be creating the "z" sound instead. Feel your throat to make sure there is no vibration.
voiced "th" sound "d" sound
Stick out your tongue and rest your top front teeth very gently on it. Use your voice as you prolong this sound. Keep your tongue and teeth lightly touching while you say it.
If you keep your tongue inside your mouth and put it behind your top front teeth, you will be creating the "d" sound instead.
"p" sound "b" sound
Place your lips completely together and then force air out of your mouth in a little explosiion. Remember that this sound does not use your voice.
The "p" and "b" look exactly the same. The only difference is that you use your voice when saying "b." If you use your voice when saying "p", you will be creating the "b" sound.