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使う， 遣う， つかう
1. to use (a tool, method, etc.), to make use of, to put to use
2. to use (a person, animal, puppet, etc.), to employ, to handle, to manage, to manipulate
3. to use (time, money, etc.), to spend, to consume
4. to use (language), to speak
使用（工具、方法等），利用，使处于可用状态；用(时间)，花(钱)，花费，消耗，耗费；使用（某人、某动物、木偶等），雇佣，处理，管理，掌控；使用（语言），说话
は
1. indicates sentence topic
2. indicates contrast with another option (stated or unstated)
3. adds emphasis
指示句子的主题；表示与另一选项（无论是否明确提及）形成对比；表示强调
に
1. at (place, time), in, on, during
2. to (direction, state), toward, into
3. for (purpose)
4. because of (reason), for, with
5. by, from
6. as (i.e. in the role of)
7. per, in, for, a (e.g. "once a month")
8. and, in addition to
9. if, although
tbd
