投入

とうにゅう

throw, investment, making (an electrical circuit)

JLPT N1

Character Breakdown

Meaning and Usage

"投入" (とうにゅう) primarily means "to throw in," "to invest," or "to put into use." It is often used in formal or business contexts to describe the act of investing resources such as money, manpower, or equipment into a project or operation.

Common Contexts

  • Financial investment: 投入 is used when talking about putting money into projects or businesses.
  • Resource allocation: It describes the act of deploying resources like machines or personnel.
  • Technical usage: In electrical or mechanical contexts, it can mean applying or introducing something like current or materials.

Collocations and Patterns

  • 資金を投入する (to invest funds): Common in business and finance.
  • 人員を投入する (to deploy personnel): Used in work or emergency situations.
  • 電流を投入する (to apply electric current): Technical or engineering contexts.

Register and Nuance

"投入" is a formal term, often found in written language, business reports, and technical documents. It is less common in casual conversation, where simpler verbs like "入れる" might be used instead.

Common Mistakes

Learners sometimes confuse "投入" with "投入れる" (which is not a word). Remember that "投入" is a noun or a suru-verb and should be used accordingly. Also, avoid using it in casual speech where it may sound too formal or stiff.

Example Sentences

あたらしいぷろじぇくとにたがくのしきんをとうにゅうした。

We invested a large amount of money in the new project.

こうじょうのせいさんらいんにさいしんのきかいをとうにゅうするよていだ。

We plan to introduce the latest machines into the factory production line.

でんきかいろにでんりゅうをとうにゅうすると、きかいがうごきはじめる。

When electric current is applied to the circuit, the machine starts operating.