壊す
こわす
kowasu
= to break / to destroy / to smash / to ruin / to wreck
壊す (kowasu) is the verb Japanese speakers reach for whenever something is deliberately or accidentally broken — from a dropped smartphone to a sabotaged negotiation. Its range stretches from snapping physical objects to destroying plans, trust, and even your own health.
壊す (kowasu) is a transitive verb, meaning the subject actively breaks an object: kare wa mado wo kowashita — he broke the window. This transitive quality is essential: 壊す always requires a direct object that receives the action.
Its intransitive counterpart is 壊れる (kowareru), meaning something breaks on its own or gets broken without specifying an agent: keitai ga kowareta — my phone broke (it just stopped working). Japanese grammar treats these as a matched pair, and mixing them up is a common learner error.
Beyond physical damage, 壊す extends naturally into figurative territory. Karada wo kowasu (体を壊す) means to ruin one’s health — often from overwork or neglecting sleep. Keikaku wo kowasu (計画を壊す) means to wreck a plan, while kankei wo kowasu (関係を壊す) means to destroy a relationship. In each case the speaker is the active agent doing the breaking.
The transitive/intransitive distinction between 壊す (kowasu) and 壊れる (kowareru) is one of the most important verb pairs in Japanese. Use 壊す when a person or force actively breaks something: kodomo ga omocha wo kowashita (the child broke the toy). Use 壊れる when the focus is on the thing that ended up broken, regardless of cause: omocha ga kowareta (the toy broke / is broken).
A common mistake is using 壊す when describing a malfunctioning machine — if it simply stopped working, 壊れる is more natural. Reserve 壊す for contexts where someone’s action caused the damage.
Note also that 壊す pairs with を, not に: kare wa jitensha wo kowashita, not jitensha ni kowashita.
The character 壊 is built from 土 (tsuchi, earth) on the left and 褱 (kai) on the right. 褱 originally depicted something wrapped or bundled up. Together the components evoke a structure bound with earth that collapses and crumbles apart — a fitting image for destruction. 壊 appears in related words such as 崩壊 (houkai, collapse/disintegration) and 破壊 (hakai, destruction/demolition), both of which carry the same sense of something falling irreversibly apart.
Everyday use
引っ越しの作業中に、うっかりテレビを壊してしまった。
Hikkoshi no saggyou-chuu ni, ukkari terebi wo kowashite shimatta.
I accidentally broke the TV while moving.
Casual / Social Media
無理な残業続きで体を壊す前に、ちゃんと休んでよ。
Muri na zangyou tsuzuki de karada wo kowasu mae ni, chanto yasunde yo.
Please rest properly before you ruin your health from all that overtime.
Formal / Cultural context
突然のシステム障害が交渉の計画を完全に壊してしまいました。
Totsuzen no shisutemu shougai ga koushou no keikaku wo kanzen ni kowashite shimaimashita.
The sudden system failure completely wrecked our negotiation plan.
In Japanese work culture, the phrase karada wo kowasu (体を壊す) carries particular weight. Overwork — karoshi (過労死) in its most extreme form — is a recognized social issue in Japan, and warnings not to break one’s body appear regularly in conversations between colleagues, family members, and even in company wellness communications. Using 壊す in this context signals genuine concern rather than casual advice.
The concept of breaking harmony or social bonds is captured in phrases like wa wo kowasu (和を壊す, to break the harmony) and fun’iki wo kowasu (雰囲気を壊す, to ruin the atmosphere). In a culture that places high value on group cohesion and reading the room (kuuki wo yomu), these expressions mark serious social missteps — disrupting a meeting’s mood or undermining group consensus is not taken lightly.
In everyday spoken Japanese, 壊す often appears with the auxiliary -te shimau (壊してしまう), which adds a nuance of regret or unintentional completion — something was broken and now it cannot be undone. This construction is so common with 壊す that learners will encounter it constantly in both conversation and written text.