Huh? How do you pronounce the name of the first letter of the word queue, and how does that differ from when you pronounce the word queue?
The most obvious difference is that queue uses unaspirated /k/ sound while quick and quack both use the aspirated /kʰ/ sound.
The most obvious difference is that queue uses unaspirated /k/ sound while quick and quack both use the aspirated /kʰ/ sound.