Hi Kareem With the exception of foreign loan words, the "k" in English is always pronounced /k/ and the "q" is always followed by a "u" to form a /kw/ sound. A good example is the word "quick" (pronounced /kwɪk/): by themselves, both the "k" and "q" take the /k/ sound, but you won't see an English word where the "q" doesn't have a "u" following it to form a /kw/. I'm not sure if I answered your question. Please let me know if I didn't.

Yes there is a difference. For example, look at the words Queen and King. Or Quilt and Kilt.