Sorry if this question has been asked before. I tried to look around for an answer but couldn't find it.
I just want to state before that my question is not regarding the verb ある or verbs with kanji + multiple hiragana (for example 負ける). The question is regarding verbs with kanji + single る.
I have some issues with the negative form of verbs ending with る. I know the basic rules for converting a verb into negative form (adding an あ-sound + ない) but i cant get a grasp on these. Sometimes it is らない and sometimes just ない. Is there a rule to when it is らない and when its just ない or is it just an irregularity?