This happens when the vowel "u" is:
1- Word initial
2- Syllable initial after alveolar consonant "l", "n", "t", "d". The combination with "t" is /tʃ/, and with /d/ is /ʤ/.
3- After velar consonants "c" (when "c" has the /k/ sound) and "g", and labio-dental consonants "f" and "v".
4- After "h" and labial consonants "m". "p". and "b"
/ju:/
Group 1: u (word initial) use, usual, university
Group 2: l/n/t/d+u (syllable initial) value, manual, actual, gradual
Group 3: c/g/f/v+u (when c sounds /k/) cute, regular, refuse, revue
Group 4: h/m/p/b+ u huge, amuse, reputation, vocabulary
Group 5: ue fuel, hue, rescue
Group 6: ew few, pew, skew
Group 7: eau beautiful, beaut (except eau de cologne and beau are pronounced /oʊ/, and bureaucracy is pronounced /ɑ:/)
When "ue" or "ew" follow a digraph such as "cl" and "ch" are pronounced /u:/.
Group 1: ue clue
Group 2: ew chew
The "ue" spelling is usually silent when it occurs at the end of a word and follows the letters "g", "ng", or "q".
Group 1: ue fatigue, tongue, unique
Exception: argue (ends in a long u sound)