JLPT N3FormalDetached

という理り由ゆうでon the grounds that

It names the reason someone gave for a decision: "on the grounds that". You are only reporting the reason, and it is often one you doubt or find unfair.

店みせは、予よ約やくが確かく認にんできないという理り由ゆうで、入にゅう店てんを断ことわった。

The restaurant turned us away on the grounds that it couldn't confirm our reservation.

外がい国こく人じんだという理り由ゆうで、部屋へやを貸かしてもらえなかった。

They wouldn't rent me the room, on the grounds that I am a foreigner.

How to form it

Plain form + という理由で

という quotes the reason as a whole sentence, so a noun or a な-adjective keeps its だ: 学がく生せいだという理り由ゆうで, 危き険けんだという理り由ゆうで. A noun often drops it: 学がく生せいという理り由ゆうで.

Before it: The reason as it was stated: 経けい験けんがない, 危き険けんだ, 若わかすぎる. だ doesn't turn into な as it does before ので: 危き険けんだという理り由ゆうで.
After it: What was decided: 断ことわった, 中ちゅう止しした, 選えらんだ. Very often it was done to you: 断ことわられた.
Said about: Mostly someone else's reason: a company's, a school's, a shop's. Your own, when you are setting out a careful choice.
Tone: Detached. という holds the reason at arm's length: that is what they said.
Where you'll meet it: News, official explanations, complaints about unfair treatment.

In use

会かい社しゃは、田た中なかさんが未み経けい験けん者しゃだという理り由ゆうで、応おう募ぼを断ことわった。

The company turned down Tanaka's application on the grounds that he had no experience.

学がっ校こうは、安あん全ぜんを確かく保ほできないという理り由ゆうで、運うん動どう会かいを中ちゅう止しした。

The school canceled the sports day on the grounds that it could not ensure safety.

私わたしは、駅えきに近ちかいという理り由ゆうで、この事じ務む所しょを選えらんだ。

My reason for choosing this office was that it is close to the station.

Your own reason, set out carefully.

The reason given, not your own "because"

彼かれは若わかいから、選えらばれなかった。

He wasn't chosen because he is young.

You are saying why. It is your own explanation.

彼かれは若わかいという理り由ゆうで、選えらばれなかった。

He wasn't chosen, on the grounds that he is young.

That was the reason given. You may well think it a poor one.

For an everyday reason of your own it sounds like an official statement.

Sounds odd: 眠ねむいという理り由ゆうで、先さきに帰かえりました。

I went home early on the grounds that I was sleepy.

In conversation: 眠ねむかったので、先さきに帰かえりました.

Close neighbours

ため・ためにN4

The formal "because" that states the cause as a fact. No one's reason is being quoted.

工こう事じのため、この道みちは通とおれません。

This road is closed for construction work.

ことからN3

A fact that a name or a conclusion rests on. Nobody gave it as their reason.

富ふ士じ山さんが見みえることから、この坂さかは「富ふ士じ見み坂ざか」と呼よばれている。

You can see Mt Fuji from it, which is why this slope is called Fujimi-zaka, "Fuji-view slope".

のでN5

The soft everyday "because", and the one for your own reasons.

時じ間かんがなかったので、朝あさご飯はんを食たべませんでした。

I didn't have time, so I didn't eat breakfast.

Check yourself

1Who says he lacks experience?

会かい社しゃは、経けい験けんが足たりないという理り由ゆうで、彼かれを採さい用ようしなかった。

Choose an answer to see why.

2Which one fits?

まだ学がく生せい（　　）という理り由ゆうで、カードを作つくれなかった。

Choose an answer to see why.

More detail

というだけの理り由ゆうで is "just because", for a reason you think is no reason at all.

若わかいというだけの理り由ゆうで、意い見けんを聞きいてもらえなかった。

Nobody would listen to my opinion, just because I am young.

More sentences

会かい社しゃは「協きょう調ちょう性せいに欠かける」という理り由ゆうで彼かれを不ふ採さい用ようにしたが、その評ひょう価かには疑ぎ問もんが残のこる。

The company rejected him on the grounds that he "lacked teamwork skills", but there is reason to doubt that assessment.

市しは、老ろう朽きゅう化かが進すすんでいるという理り由ゆうで、その橋はしを通つう行こう止どめにした。

The city closed the bridge to traffic on the grounds that it was getting too old.

彼かの女じょは、専せん門もんが違ちがうという理り由ゆうで、共きょう同どう研けん究きゅうへの参さん加かを辞じ退たいした。

She declined to take part in the joint research, giving as her reason that it was outside her field.