Phoneme and letter represent respectively the sounds (speaking) and the graphic signs (writing). Phonemes are the sound units that make up the speech and letters, are the graphic signs that make writing possible. Together and in an a certain sequence and form, letters make up the alphabet.

Example 1
coçar = 5 letras
/k/ /o/ /s/ /a/ /r/ = 5 fonemas
Example 2
máximo = 6 letras
/m/ /á/ /s/ /i/ /m/ /o/ = 6 fonemas
Although the number of phoenems and letters coincide in many words, it is not always the case.
Exemplo 1:
acesso = 6 letras
/a/ /c/ /e/ /s/ /o/ = 5 fonemas
Exemplo 2:
chute = 5 letras
/x/ /u/ /t/ /e/ = 4 fonemas
How are Phoenems classified?
We can classify these by vowels, consonants and semi-vowels ( vogais, consoantes e semivogais).
Vogais / Vowels
Are all sounds issued without obstacles only throuth the mounth (a, e, i , o, u), or by the mouth and the nasal cavities (ã, ẽ, ĩ, õ, ũ).
Examples:
pia, ando, cesto, quero, lente, li, lindo, sonho, avó, som, susto, untar.
Consoantes / Consonants
Consonants find obstacles during its passage throughthe mouth, hence, they always need to be followed by vowels.
Examples:
base, deduzir, falar, pedaço, redigir, sintetizar.
Semivogais / Semi Vowels
Semi vowels are the /i/ e /u/ phoenems that appear together with a vowel, forming a syllabus. Its important to note that, while vowels are essential in the formation of syllabus, semi vowels aren't.
Examples:
cárie, mau, pais, rei, seita, venceu.
Letras / Letters G and J
Letters G and J may represent the same phoenem when they are next to the vowels E and I: ge = je and gi = ji.
Example 1:
singelo = 7 letras
/s/ /ĩ/ /j/ /e/ /l/ /o/ = 6 fonemas
Example 2:
refúgio = 7 letras
/r/ /e/ /f/ /ú/ /j/ /i/ /o/ = 7 fonemas
Letra / Letter H
In the begining of the word, the letter H is not a phoneme.
Example 1:
harpa = 5 letras
/a/ /r/ /p/ /a/ = 4 fonemas
Example 2:
hoje = 4 letras
/o/ /j/ /e/ = 3 fonemas
Letras / Letters M and N
Whereas letters M and N have a nasal function, they aren't considered phonemes.
Example 1:
campo = 5 letras
/k/ /ã/ /p/ /o/ = 4 fonemas
Example 2:
atento = 6 letras
/a/ /t/ /ẽ/ /t/ /o/ = 5 fonemas
Whereas letters M and N don't have a nasal function, they are considered phonemes.
Example 1:
navio = 5 letras
/n/ /a/ /v/ /i/ /o/ = 5 fonemas
Example 2:
soma = 4 letras
/s/ /o/ /m/ /a/ = 4 fonemas
Letra / Letter X
The letter X may represent the phonemes /s/, /z/ e /ks/.
Example 1:
sexto = 5 letras
/s/ /e/ s/ /t/ /o/ = 5 fonemas
Example 2:
exalar = 6 letras
/e/ /z/ /a/ /l/ /a/ /r/ = 6 fonemas
Example 3:
fixo = 4 letras
/f/ /i/ /k/ /s/ /o/ = 5 fonemas
Dígrafos or Consonantic sounds
Besides the above letters, we also find consonantic sounds in the Portuguese Language. This means that two letters together issue one phoneme.
Examples:
ch: chuva /x/ /u/ /v/ /a/
nh: arranhar /a/ /rr/ /a/ /nh/ /a/ /r/
qu: quindim /k/ /ĩ/ /d/ /ĩ/
rr: aborrecer /a/ /b/ /o/ /rr/ /e/ /c/ /e/ /r/
sc: nascer /n/ /a/ /c/ /e/ /r/
Do you feel brave enough to try some exercices?
Exercícios / exercices
1. In which of the words below we can find more letters then phonemes?
a) achado b) táxi c) cadeira d) surpresa e) redigir
Answer: a achado = 6 letras
/a/ /x/ /a/ /d/ /o/ = 5 fonemas
Following alternatives: b: táxi = 4 letras
/t/ /á/ /k/ /s/ /i/ = 5 fonemas
c: cadeira = 7 letras
/c/ /a/ /d/ /e/ /i/ /r/ /a/ = 7 fonemas
d: surpresa = 8 letras
/s/ /u/ /r/ /p/ /r/ /e/ /z/ /a/ = 8 fonemas
e: redigir = 7 letras
/r/ /e/ /d/ /i/ /j/ /i/ /r/ = 7 fonemas
2. Identify the letters and the phonemes below:
a) habilidoso
Answer
habilidoso = 10 letras
/a/ /b/ /i/ /l/ /i/ /d/ /o/ /z/ /o/ = 9 fonemas
b) andar
Answer
andar = 5 letras
/ã/ /d/ /a/ /r/ = 4 fonemas
c) nascimento
Answer
nascimento = 10 letras
/n/ /a/ /c/ /i/ /m/ /ẽ/ /t/ /o/ = 8 fonemas
d) gabar
Answer
gabar = 5 letras
/g/ /a/ /b/ /a/ /r/ = 5 fonemas
e) exílio
Answer
exílio = 6 letras
/e/ /z/ /í/ /l/ /i/ /o/ = 6 fonemas
f) hipótese
Answer
hipótese = 8 letras
/i/ /p/ /ó/ /t/ /e/ /z/ /e/ = 7 fonemas
g) mundo
Answer
mundo = 5 letras
/m/ /ũ/ /d/ /o/ = 4 fonemas
h) osso
Answer
osso = 4 letras
/o/ /s/ /o/ = 3 fonemas