1. auxiliary verb indicating the causative voice (～せる connects to -nai stem of 五段 verbs and to サ変 as さ～せる; ～させる connects to -nai stem of 一段 and カ変 verbs and to サ変 as せ～させる)

2. auxiliary verb indicating the granting of permission to do something

3. auxiliary verb used as an honorific for others' actions (Honorific, as 〜(さ)せられる, あら〜せられる, 〜(さ)せ給う, etc.)