The letter H (hache, [`ache]) is never pronounced. It helps to distinguish between the words with the similar pronunciation, such as:
hola [`ola] – hellow
ola [`ola] – wave
The combination СH (ce hache) is pronounced like the English [ʧ] in chair.
The sound [f], similar to the English ph, is represented by the letter F (efe). Remember, there is no combination ph in Spanish:
Filosofía = Phylosophy
The sound [s] in Spain is pronounced between the English “s” and “sh”: the tip of the tongue is placed not on the the tooth ridge, but on the hard palate. This sound is represented by the letter S (ese), which is not voiced between two vowels, so there is no double ss in Spanish!!!
CORRECT: profesor
INCORRECT:professor
In Latin America, this sound is pronounced like the English “с” in cinema.