Here's why:
* The schwa sound (ə) is a very common, unstressed vowel sound. It's often described as a "short u" or "uh" sound.
* In "change", the "a" is unstressed. This means it doesn't get the full pronunciation like the "a" in "cat" or "car".
* Therefore, the "a" in "change" is pronounced with the schwa sound (ə).
So, the pronunciation of "change" is roughly: chānj (with the "a" sounding like "uh").