quarantine -|- The letter q will always be followed by a u to create the "kwa" sound.  

quantity -|- Spelled exactly like it sounds with a qu- to start it off. Beak it up and sound it out: quan – ti- ty 

quite -|- It's quite similar to quiet, except the –e and –t switch places.  

queue -|- queue mean to be in line, so just remember there are 2 -ue's in line behind q. 

quiet -|- E.T. was quiet

questionnaire -|- There's no question about it, there's an ‘air' in this word. Combine them in two parts: question + naire