～かねない
might well / is liable to
～かねない attaches to the ます-stem of a verb and warns that something bad could easily happen. It maps to English “might well do” or “is liable to do”.
Be careful: the ない at the end does not make this negative. The whole unit かねない means “might do”, the exact opposite trap of ～かねる, which looks affirmative but means “cannot do”.
Warning that something undesirable could happen
Use ～かねない when you judge that a person or situation could realistically lead to a bad outcome. It is almost always used for negative possibilities, not good ones.
彼はそんなことを言いかねない。
“He might well say something like that.”
- 彼（かれ）= he
- は = topic marker
- そんな = that kind of
- こと = thing
- を = object marker
- 言いかねない（いいかねない）= might well say
It is also common with situations rather than people, often after a conditional clause.
急いで運転すると、事故を起こしかねない。
“If you drive in a hurry, you might well cause an accident.”
- 急いで（いそいで）= in a hurry
- 運転すると（うんてんすると）= if (you) drive
- 事故（じこ）= accident
- を = object marker
- 起こしかねない（おこしかねない）= might well cause
How to form it
Verb ます-stem + かねない
- 言う（いう）= to say → 言いかねない（いいかねない）= might well say
- する = to do → しかねない = might well do
- 起こす（おこす）= to cause → 起こしかねない（おこしかねない）= might well cause
Key idea
～かねない means “I wouldn't put it past this person/situation”: despite the ない, it asserts that an undesirable outcome is a real possibility.
Built on the same stem
Updated .