In Spanish the letters k and qu sound exactly the same as in the word "car". The only difference is that "k" can go next to all the vowels. The letter "qu" is acompannied only by the vowels "e, i". Let's see a few examples:

k
Yo practico karate.
     I practice karate.
Juan y yo jugamos al póker.
     Juan and I play poker.
un kilo de peras.
     one kilogram of pears
el oso koala
     koala bear
kiosco de periódicos pequeño
     small newsstand

qu
Abra este paquete.
     Open this package.
casa pequeña
     small house
Aquí está.
     Here it is.
No lo quiero.
     I don't want it.
Es un éxito de taquilla.
     It is a blockbuster.