完成をする

Grammatically, it’s a standard Noun + を + する verb. You take 完成 (completion) and pair it with する (to do). You can use it as a simple 完成する or add the を for a bit more emphasis on the object you're working on. It’s transitive, meaning you are the one doing the finishing. Common partners for this phrase include 作品 (sakuhin - work of art), 家 (ie - house), or レポート (report - if it's a big, meaty one). You'll often see it in the past tense, 完成をしました, because the moment of completion is a cause for celebration. It’s like hitting the "Save and Export" button on your life’s work. Just don't use it for your morning coffee unless you've spent three hours on the latte art.

Imagine you’re a YouTuber who finally finished editing a 20-minute vlog. You’d tweet, 動画を完成をしました！ (I finished the video!). Or maybe you're playing a simulation game like SimCity and your massive stadium is finally done—the notification might say スタジアムが完成しました. In the professional world, an architect might tell a client, 来月までにビルを完成をします (We will complete the building by next month). Even in the kitchen, if you’ve spent all day making a complex beef bourguignon, you can proudly announce its completion. It’s the language of effort meeting results. It’s the verbal equivalent of a "100% Complete" badge in a video game. If life had a trophy system, this phrase would trigger the gold one.

Use 完成をする when the end result is a tangible or intangible "product." Think about things that have a structure or a design. A puzzle, a bridge, a software update, or a long-form novel are all perfect candidates. It’s also great for social media captions when you’ve finally finished a DIY project that took way too many trips to the hardware store. It conveys a sense of achievement. If you feel like taking a photo of what you’ve done, you should probably use 完成. It’s for the moments where you want to show off just a little bit. It's the "look what I made!" of the Japanese language.

Don't use it for things that just... stop. If you're finishing a conversation, use 終わる. If you're finishing a meal, use 食べ終わる. Using 完成 for a sandwich is a bit much unless that sandwich has architectural blueprints. Also, avoid it for administrative tasks that feel like "processing" rather than "creating." For bank transfers or form submissions, 完了 (kanryo) is your boring, office-appropriate friend. 完成 is too poetic for a tax return. Also, don't use it for people—unless you're a mad scientist building a cyborg. Saying you "completed a person" sounds like a plot for a very weird sci-fi movie.

Homework isn't a masterpiece; it's a chore. Using 完成 makes it sound like your math worksheet is the Mona Lisa.

A meeting isn't built; it just happens. Unless the meeting results in a physical tower of paper, stick to 終える.

Another common slip is confusing it with 完了する. Remember: 完成 is for creators, 完了 is for bureaucrats. If there's no beauty or structure involved, skip the 完成. Also, watch out for the particle. While 完成する is common, adding the を makes it more deliberate. Just don't accidentally say 完成になる—that’s like saying "to become a completion," which sounds like a very confused Zen koan.

If 完成をする is too heavy, try 仕上げる (shiageru). It means "to put the finishing touches on." It’s like the difference between building the house and painting the shutters. Then there’s 完了する (kanryo suru), which is the clinical, robotic version of "complete." Use it for software downloads or paying bills. For things you build from the ground up, 作り上げる (tsukuriageru) is a great, muscular alternative. It emphasizes the sweat and tears you put into the process. If something just naturally comes to an end, 終わる (owaru) is your reliable, no-frills option. It’s the vanilla ice cream of finishing verbs.

In casual speech, people usually drop the を and just say 完成した！ (Finished!). If you want to say something "is completed" (passive/intransitive), you use 完成される or simply the intransitive 完成する where the object becomes the subject: 家が完成した. To sound more professional, you might use 完成の運びとなりました (We have reached the stage of completion), which is a fancy way of saying "we're done." There's also 完成予定 (kansei yotei), which means "scheduled for completion"—a phrase you'll see on every construction site in Tokyo. If you're talking about a project that's almost there, you can say 完成間近 (kansei majika).

Is 完成する the same as 終わる? No, 終わる is just "to end," while 完成 is "to achieve completion of a project." Can I use it for a drawing? Yes, it's perfect for art! Is it formal? It's neutral, but adding を makes it slightly more formal and deliberate. What about video games? Yes, getting 100% completion is 完成. Does it work for weight loss? Not really; that's more like 目標達成 (achieving a goal). It’s for things you build or make. If you didn't create it, you probably didn't 完成 it. Unless you're building a new body at the gym, then maybe!