You will never see, in the English language, the letter q without a u following it. The exception here is in proper names, like Q-tip, but that is the only exception. The rest of the time, qu is always together.
For this reason, in OG, Qu is a consonant together and the sound it makes is “kw.”
After I learned this, I started thinking of words and sure enough, qu is always together.
Queen, quarter, quilt, quill, quiet, quite, quick, quit, question, quack, quality, quip, quintuplet, quagmire, squint, squat, squirt, squirrel … I could keep going but I’m sure you get the point.
Qu is always together, and together it is considered a consonant.
Consonants b, c, d, f, g, h, j, k, l, m, n, p, q(u), r, s, t, v, w, x, y, z
Vowels a, e, i, o, u, y