j

Palatal approximant
The voiced palatal approximant is a type of consonantal sound used in many spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨j⟩. The equivalent X-SAMPA symbol is j, or equivalently, i_^, and in the Americanist phonetic notation it is ⟨y⟩. Because the name of the letter jay may be confusing when used to refer to this sound, the palatal approximant is sometimes called yod instead, as in the phonological history terms yod-dropping and yod-coalescence.
The palatal approximant is the semivocalic equivalent of the close front unrounded vowel [i]. The two are almost identical featurally. They alternate with each other in certain languages, such as French, and in the diphthongs of some languages, ⟨j⟩ and ⟨i̯⟩ with the non-syllabic diacritic are used in different transcription systems to represent the same sound.
In the writing systems used for most of the languages of Central, Northern and Eastern Europe, the letter j denotes the palatal approximant, as in German Jahr 'year'. This is the IPA usage, and although it may be counter-intuitive for English speakers, it does occur with this sound in a few English words, such as hallelujah and Jägermeister.
In grammars of Ancient Greek, the palatal approximant, which was lost early in the history of Greek, is sometimes written as ⟨ι̯⟩ (iota with the inverted breve below, the non-syllabic diacritic or marker of a semivowel).

Features

• Its manner of articulation is approximant, which means it is produced by narrowing the vocal tract at the place of articulation, but not enough to produce a turbulent airstream. The type of approximant is glide or semivowel. The term glide emphasizes the characteristic of movement (or 'glide') of /j/ from the /i/ vowel position to a following vowel position. The term semivowel emphasizes that, although the sound is vocalic in nature, it is not 'syllabic' (it does not form the nucleus of a syllable).
• Its place of articulation is palatal, which means it is articulated with the middle or back part of the tongue raised to the hard palate.
• Its phonation is voiced, which means the vocal cords vibrate during the articulation.
• It is an oral consonant, which means air is allowed to escape through the mouth only.
• It is a central consonant, which means it is produced by directing the airstream along the center of the tongue, rather than to the sides.
• The airstream mechanism is pulmonic, which means it is articulated by pushing air solely with the lungs and diaphragm, as in most sounds.