Home/Vocab Vault/徹する徹する徹するてっするto penetrateN1Suru VerbFreq. #8048Meanings1to penetrate2to sink in3to devote oneself (to)4to do intently and exclusively5to do throughout (e.g. the night)ConjugationsFormJapanesePolite (ます)てっしますて-formてっしてPast (casual)てっしたPast (polite)てっしましたNegative (casual)てっしないNegative (polite)てっしませんShow all 12 formsRelated WordsSame Kanji徹夜てつやstaying up all night徹底てっていthoroughnessLearn MoreGrammar〜てte-form (connecting)〜ますpolite verb ending〜でしたwas (polite past)〜ができますcan do ~受身形passive (be done to)Practice 徹する in JIVXReinforce this word with AI-graded sentence practice and spaced repetition.Start Practicing Free