When we want to explain something but we don't know the exact or accurate amount, we can use words like, "approximately" or about" or "roughly. This is to explain an estimation.
"Approximately 20% of the students are Japanese!"
"Roughly 20% of the students are Japanese!"
"The Japanese student body is about 20%!"
正確な数量が分からないことについて説明するときには、"approximately" や "about" "roughly" などの言葉が使えます。これは、見積もりを伝えます。
"Approximately 20% of the students are Japanese!"
"Roughly 20% of the students are Japanese!"
"The Japanese student body is about 20%!"
（生徒の約20％が日本人です）
Japanese students made up about 20% of the students at language school
At language school 20% of the students are Japanese
"made up about" used frequently and is a casual way of describing many situations i.e "Japanese students made up about 20% of the students at language school" and "Nike shoes made up about 80% of my shoe collection. describing how much of something there is.
"made up about" はよく使われるカジュアルな表現です。これはいろいろな状況を表します。
例：
"Japanese students made up about 20% of the students at language school"（その語学学校の生徒のおよそ20％は日本人でした）
"Nike shoes made up about 80% of my shoe collection."（私の靴のコレクションの8割はナイキです）
"made up about" はものの多さを表します。
More or less one fifth of the student population at the language school is made up of Japanese students.
Roughly 20 percent of the students are Japanese.
More or less' is used as a synonym for 'about'.
The 'student population' means all of the students at the
language school.
One fifth and 20% are equivalent numbers. I.e. 20% is equal to 1/5 or one fifth.
'Roughly' is used as a synonym for the other two terms
mentioned earlier, i.e. 'about' and 'more or less'.
More or less' は 'About'（約／およそ）の同義語です。
'Student population' は語学学校の生徒全員を指します。
"One fifth"（5分の1）と "20%" は同義です、つまり20パーセントというのは5分の1のことですね。
'Roughly' は、先に言及した二つの単語、つまり 'More or less' と 'About' の同義語です。
Around 20% of students attending the school are Japanese
If you would like to mention that 20% of students at a certain English school are Japanese, you can relate that fact in the form of the above example statement.
In American English, when indicating an approximate amount, we use the less formal words 'about' and 'around'. So we might say something like 'There are about 12 students in my class.' or 'There were around 12 disciples at the supper table.' We can also use the phrase 'something like', which is even a bit less formal than 'about' and 'around'; so we might say 'There is something like 20 balloons in the air above Kakuda today.' We use the singular verb 'is' in this case because the object isn't so much 'balloons' as it is the implied concept of 'number' or 'phenomena'. I hope that this is useful to you in your studies.
アメリカ英語では、'approximate'（おおよそ）の数量を言う場合、よりインフォーマルな 'about' と 'around' という言葉を使います。
例えば：
'There are about 12 students in my class.'（私のクラスには生徒が12人くらいいます）
'There were around 12 disciples at the supper table.'（晩餐の席には弟子が12人くらいいました）
さらにインフォーマルな 'something like' というフレーズを使うこともできます。
例えば：
'There is something like 20 balloons in the air above Kakuda today.'（今日Kakudaには20機くらいの気球が上がっています）
この場合は 'balloons'（気球）というよりも数字や現象を指しているので三人称単数の 'is' を使います。
参考になれば幸いです。
At that school, roughly 20% of the students are Japanese.
If you want to explain that about 20% of the students at a school are Japanese, you can say:
"Approximately 20% of the students are Japanese."
"At that school, roughly 20% of the students are Japanese."
ある学校の生徒の20％が日本人であることは、次のように表せます。
"Approximately 20% of the students are Japanese."（生徒の約20％が日本人です）
"At that school, roughly 20% of the students are Japanese."（その学校では生徒の約20％が日本人です）
When explaining that 20% of students are Japanese you don't always have to say 20%. You can say "One out of Five students are Japanese". That sounds more impressive than 20%. "One Fifth of students are Japanese" is also acceptable but they all mean the same in the end.
生徒の20％が日本人であることを言うには、必ずしも20％と言う必要はありません。
"One out of Five students are Japanese"
（5人に1人は日本人です）
これは、20％というよりすごく聞こえます。
"One Fifth of students are Japanese"
生徒の5分の1は日本人です）
これも使うことができますが、結局は同じ意味になります。
Japanese students account for 20 percent of the students at this language school.
Around 20% of the students at this language school are Japanese.
おっしゃられている内容は、以下のようにも表現できると思いました(*^_^*)
Japanese students account for 20 percent of the students at this language school.
「日本人生徒はこの語学学校の生徒の20％を占める」
Around 20% of the students at this language school are Japanese.
「この語学学校の生徒の２０％が日本人です」
account forは「割合を占める」という時によく使われるフォーマルな表現です。
以上です。
少しでも参考になれば幸いです(*^_^*)
★★大阪カフェレッスン英会話講師KOGACHI
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