Rules of the letter J
The letter J (jota) sounds the same as the letter G (ge) when the vowels that are behind are E or I ( JE-GE, JI-GI ), for this reason it can be difficult to differentiate what words are written with J.
Rules of Words that are written with J
Nº. 1
Words derived from nouns or adjectives ending in ja, jo.
of caja: cajero, cajetilla , cajista, cajita, encaje
pf viejo: vejez, viejito, vejestorio
of ojo: ojeras, ojeriza, ojitos, ojear
Nº. 2
Words that start with adj and by obj.
Nº. 3
The words ended in aje and by eje.
Exceptions:
Nº. 4
The past and subjunctive verb forms of verbs whose infinitive ends indecir, ducir, traer.
Nº. 5
Verbal forms of verbs whose infinitive ends in jar - jear.
Nº. 6
Nouns and adjectives ending in jero, jera, jería.
Exceptions:
Nº. 7
Words derived from Latin subiectare (someter, poner debajo).
In addition to the exceptions that appear in the rules, derivatives are also exceptions.