Because the English name of the letter J, jay, starts with [dʒ] (voiced postalveolar affricate), the approximant is sometimes instead called yod[citation needed], as in the phonological history terms yod-dropping and yod-coalescence.

The palatal approximant can often be considered the semivocalic equivalent of the close front unrounded vowel [i].

Eugenio Martínez Celdrán describes the difference between them as follows (with audio examples added):[9] [j] is shorter and is usually a merely transitory sound.

Thus, in words like viuda [ˈbjuða]ⓘ 'widow', Dios [ˈdjos]ⓘ 'God', vio [ˈbjo]ⓘ 's/he saw', etc., the semi-vowel [j] is unrounded; if it were rounded, a sound that does not exist in Spanish, [ɥ], would appear.

I think that the former is a real consonant, whereas the latter is a semi-consonant, as it has traditionally been called in Spanish, or a semi-vowel, if preferred.

In the writing systems used for most languages in Central, Northern, and Eastern Europe, the letter j denotes the palatal approximant, as in German Jahr 'year', which is followed by IPA.

Although it may be seen as counterintuitive for English-speakers, there are a few words with that orthographical spelling in certain loanwords in English like Hebrew "hallelujah" and German "Jägermeister".