The word "jerk up down" may initially seem confusing in its spelling. However, with the use of the International Phonetic Alphabet (IPA), its pronunciation becomes much clearer. The first word, "jerk", is pronounced with a dʒ sound as in "judge" and an ɜː sound as in "herd". The second word, "up", is pronounced with an ʌ sound as in "hut" and a p sound. The final word, "down", is pronounced with a d sound and an aʊ sound as in "now". Therefore, "jerk up down" is pronounced as "dʒɜːk ʌp daʊn".