Here's why:
* Schwa sound: The schwa sound is a very short, unstressed vowel sound represented by the symbol "ə". It often occurs in unstressed syllables.
* Syllabification of "umbrella": "Umbrella" has three syllables: um-brel-la.
* Stress: The stress falls on the second syllable "brel". The first and third syllables are unstressed but do not contain the schwa sound.
Therefore, "umbrella" does not have a schwa syllable.