Japanese by Example
Learning through examples in manga

Leaving something as-is with 〜っぱなし

っぱなし is appended to a verb stem to show that something has been left in the state or condition from that action, with a negative connotation to leaving it as such.

ぱなし comes from the verb (はな)す.

Further reading

Examples

ポケットモンスタースペシャル » Volume 5 » Page 92
よつばと! » Volume 9 » Page 143
からかい上手の(元)高木さん » Volume 11 » Page 34