Here's why:
* Stress: The word is stressed on the second syllable ("dic-TION-ary").
* Unstressed Vowels: Unstressed vowels often have a reduced sound, closer to the "uh" sound.
* Sound: In "dictionary," the "a" in the first syllable is pronounced more like "uh."
Let me know if you'd like to explore other words with unstressed letters!