The consonant q is a uvular plosive.
Usually this consonant is followed by the vowel u. The majority of the words that are currently used follow the pattern: q+ u.
However, there are some exceptions.
- queen, question, quiz.
- Iraq, Qatar, qwerty (and some other loan-words mostly from Arabic).
- Q is almost always followed by u;
- Q without a u following is mostly used in words from other languages.
There is no rule to distinguish the difference.