The letter j usually corresponds to the sound /dʒ/, however there are some exceptions.
The letter j can be pronounced as:
j = /dʒ/
- jail, jam, jump;
j = /ʒ/
- bijou, jongleur;
j = /h/
J represents a voiced palato-alveolar sibilant affricate, produced by first stopping the air flow entirely, then directing it with the tongue to the sharp edge of the teeth, causing high-frequency turbulence. We usually pronounce j as [dʒ]. However there are exceptions: loan words that include /j/ with the pronunciation of the original language.
The same sound is also made by “g”, as in giraffe.