Kotomora
JLPT N2Construction
Furigana

たことにするTreat an event as if it happened

Deliberately treats an event as having happened—or not happened—even though the actual facts are different. It can establish a harmless fiction, count one action as a substitute for another, or conceal an inconvenient fact.

The facts and the chosen account

The past form before ことにする names the event that will be counted or represented as having happened. The context must separately show that reality was different; the construction does not make the chosen account literally true.

A harmless shared fiction

じっさいにはりょこうけなかったが、いえかくりょうつくって、かいいっしゅうしたことにした

We could not actually travel, but we cooked dishes from different regions at home and treated it as though we had traveled around the world.

Analyze

The first clause states the reality; the second establishes the playful alternative account.

Counting one action as another

The two events do not always have to be direct opposites. One action can be given the practical status of another—for example, recorded study may count as attendance, or a simple drink may count as breakfast.

An agreed working account

じっさいには昨日きのうかいなかったが、ろくんだので、しゅっせきしたことにしてぎょうすすめる。

I did not actually attend yesterday's meeting, but since I read the minutes, we will proceed with the work as though I had attended.

Analyze

Attendance is not claimed as a fact; it is being assigned as the practical status used from this point onward.

Ethically sensitive concealment

じっさいにはほうこくけていたが、せきにんのがれるため、ほうこくけなかったことにした

The person had in fact received the report, but treated it as though it had never been received in order to avoid responsibility.

Analyze

The grammar is neutral, but here the chosen account deliberately conceals a fact.

Treatment, mindset, and outward pretense

たことにする changes how an event is counted or represented. たつもりで instead adopts an as-if mindset as a basis for action, while ふりをする describes outward pretense. In formal rules and analytical writing, ものとする is commonly used to deem or assume something to be the case.

More examples

じっさいにはちょうしょくつくれなかったが、ぎゅうにゅう果物くだものものんで、ちょうしょくったことにした

I could not actually make breakfast, but I had a milk-and-fruit drink and counted that as having eaten breakfast.

Analyze

こたえをさきいてしまったが、かなかったことにしてぶんもんだいいてみる。

I heard the answer beforehand, but I will disregard that and try solving the problem myself.

Analyze

じっさいにはけんしゅうられなかったが、ろくぜんれば、さんしたことにしてもらえる

I could not actually attend the training, but if I watch the entire recording, they will count me as having participated.

Analyze

このすうてしまったが、しんこうへいたもつため、なかったことにしてください

You have seen this figure, but to keep the review fair, please disregard it as though you had not seen it.

Analyze

しんせいしょりのよくじつとどいたが、たんとうしゃげんないとどいたことにしてじゅした。

The application arrived the day after the deadline, but the staff member accepted it as though it had arrived on time.

Analyze

さいいちもんけなかったが、おまけでせいかいしたことにしよう

We could not solve the last question, but let's count it as correct as a bonus.

Analyze
たことにする (takotonisuru) – Treat an event as if it happened