From A to Z;Primary
In Latin q opens many questioning words - quo, quis, quae - which is perhaps why q has such quizzical associations. Latin also provided a wide numerical lexicon from quattuor (four) and quinque (five). In such Latinate words we pronounce qu like the Old English cw (two phonemes), while in words imported more recently from French (such as antique and quiche) we pronounce it as k (one phoneme).
The queue (a pretty roundabout spelling for a word that sounds like its own initial letter) creates spelling problems for some children. They benefit from knowing its original, highly evocative French meaning (an animal's tail), and from rhythmic recitation of the letters: "Q-UE-UE".
This is what spelling lessons should be about - savouring the sounds and stories of English, and thus making the spelling memorable.
Rules can help too, and one of the most consistent dinned into infant heads by generations of teachers is that You Never Write a Q Without a U. Pupils trying to prove you wrong may find exceptions such as coq au vin and Qatar, but these are clearly exotic borrowings. You are on trickier ground, however, with a word becoming more widespread every day, as computers introduce more and more children to the qwerty keyboard.