忘れないようにメモしておきます

N5 ない nai there isn't, doesn't have N3 メモ memo memo, note, memorandum

N3 忘 bou / wasu.reru forget, oublier, olvidar

N4 〜ておく te oku Indicates an action done in advance as preparation, attaches to the te-form verb, means do beforehand N4 〜ようだ you da Indicates assumption based on evidence or impression, attaches to verb adjective or noun, means it seems that N5 〜ます masu Used at the end of verbs, polite present or future form, makes the sentence more polite N4 〜し shi Indicates multiple reasons or qualities, connects clauses or adjectives, means besides that, and also N5 〜に ni Indicates destination, target, arrival point, specific time, or person receiving an action N5 〜よ yo Sentence ending particle adding information to listener, emphasizes statement, expresses certainty or warning