Common words:
* Quick
* Quake
* Queen
* Quiet
* Quilt
* Quip
* Quiz
* Quote
* Quotient
Less common words:
* Quad
* Quadrant
* Quadratic
* Quail
* Qualify
* Quantity
* Quarrel
* Quarter
* Quartet
* Quash
* Queasy
* Quest
* Question
* Queue
Proper nouns:
* Quentin
* Quebec
* Quetzalcoatl
Let me know if you'd like to explore more words with "qu" in the first syllable, or if you have a particular topic or theme in mind.