Here's why:
* The "i" in "cousin" is pronounced as a schwa sound. A schwa sound is a very short, unstressed vowel sound represented by the symbol "ə".
* The stress in the word "cousin" falls on the first syllable "cou". This means the second syllable "sin" is unstressed, resulting in the "i" being pronounced as a schwa sound.
Therefore, the word "cousin" is pronounced like "cuhz-ən".