write + for -ing
kaku no ni
for -ing; (used/needed) to do — marks the purpose an evaluative predicate is measured against
meaning: for writing
魚を切るのに、このナイフは便利だ。
sakana o kiru no ni, kono naifu wa benri da.
This knife is handy for cutting fish. neutral
この道具、瓶のふたを開けるのに便利なんだよね。
kono dougu, bin no futa o akeru no ni benri na n da yo ne.
This tool's handy for opening bottle lids, you know. casual