「病気なので、学校で欠席しました」の訳になります。休むは「take a rest/break」という意味がありますが、「take a break from school」はしばらく学校に来ないということです。欠席の「absent」を使用します。
absent = 欠席
absent from school = 学校を欠席
学校や仕事を休むことは「skip」すると言います。
また、病気にかかってしまったことは「get sick」（過去形：was sick）です。
したがって、「I skipped school because I was sick」をお勧めします。
学校に電話して「今日病気で休みます」と言うときは「I'm sorry, I have to skip school today because I'm sick」と言います。
To explain this is simple. You can say I didn’t go or didn’t attend school. When you say this it conveys the thought that you weren’t there. Also when you add because I was sick it gives the reason why you weren’t there. So when you combine these two thoughts together you get the explanation as to why you weren’t at school.
これを伝えるのはシンプルで、I didn’t go（行かなかった）や didn’t attend school（学校に行かなかった）ということができます。
こう言うと、学校には行かなかったことが伝わります。because I was sick （病気だったから）と付け加えることで、どうして欠席したのか理由を伝えることができます。これら2つをつなげることで、どうして学校に行かなかったのかを伝えることができます。
I didn't go to school today because I have the flu.
I have flu and will not attend school.
absent - not present
flu - short for influenza is an infection that affects your respiratory (breathing) and it is caused by viruses.
When you say you are absent, it means that you will not be present. So to not be present because of an illness, you would use the first sentence.
You will use the second sentence when you are asked by someone why you were not at school and your reason would be flu.
You can use the third sentence when you are sick already and are informing the principal or teacher that you will not be at school.
Catching the flu is a horrible experience, we need to take time off for rest because we will not be productive at work or school.
The flu is contagious so staying away from others will be helpful.
Taking natural remedies is great for the body even though it seems to produce a slower healing process.
Absent: not present
"I will not be coming into class today, I have horrible flu."
インフルエンザにかかると大変ですね。仕事や学校に行っても集中できないでしょうから、休みを取らないといけません。
インフルエンザはうつるので、あまり人に近づかない方がいいでしょう。
時間はかかりますが、自然療法だと体に負担がかかりません。
Absent: 欠席している
"I will not be coming into class today, I have horrible flu."
（今日は学校を休みます。ひどいインフルエンザです）
I was absent from the gym class due to illness. I was unable to attend, I was sick.
The flu /sickness or a fever can strike at any time...
We may find the need to write a note or perhaps verbally explain why we were AWOL.(absent without leave) Or missing from a class or event?
In this scenario we could use the term: "absent due to"...(cause =illness)
Or perhaps choose to say " I was unable to attend because" ...(excuse here).
インフルエンザ、風邪、熱はいつでもくるものです。クラスや行事に欠席することを伝えるために、AWOL.(absent without leave) や missing from a class or eventと書いたり、口頭で伝える必要があるかもしれません。
この場合、"absent due to"（～のために欠席します）をいうフレーズを使うことができます。もしくは、" I was unable to attend because"（～の理由で出席できません。）と言うこともできます。
You can either just say you were sick (this is generic) or you can give a more specific answer and explain what type of sickness you had - for example: the flu or a cold; a bad headache/ a stomach bug etc.
To say that you were feeling sick implies that you don't know the exact cause for your sickness and that it was reasonably short in duration before you got better again.
The word 'because' indicates the reason for the first statement/ part of the sentence.
The word 'so' indicates the result of the first statement/ part of the sentence.
漠然と単に「病気だった」と伝えることもできますし、あるいはより具体的に病気の種類に言及することもできます。
例えば：
"the flu"（インフルエンザ）
"a cold"（風邪）
"a bad headache"（ひどい頭痛）
"a stomach bug"（お腹の風邪）
"I was feeling sick" は、「病気の原因は分からない」そして「比較的早期に良くなった」というニュアンスです。
'because' は文の前半部分の理由を伝えます。
'so' は文の前半部分の結果を伝えます。
I came down with the flu, and so I couldn't go to school.
I missed school because I was feeling sick with the flu.
I came down with the flu, and so I couldn't go to school. To "come down" with an illness is an informal way of seeing that you got that illness. This response emphasises that the reason you didn't go was because you had a flu.
I missed school because I was feeling sick with the flu. It is important to explain what your sickness was (flu) otherwise it might your explanation sounds too vague and therefore less believable.
I came down with the flu, and so I couldn't go to school.
（インフルエンザになったから、学校に行けなかった。）
病気が "come down" するとは、病気になったことを表すカジュアルな表現です。学校に行かなかった理由は、インフルエンザになったからといういことを強調しています。
I missed school because I was feeling sick with the flu.
（インフルエンザで具合が悪かったから、学校を休んだ。）
これは、インフルエンザであることを伝えることが大事です。そうしなければ、とても曖昧に聞こえ、信憑性に欠けてしまうかもしれません。
Example sentences: I've got flu so I missed school. I cached the flu that's why I missed school. I caught flu and missed school. Jenny has the flu so she missed school. She had flu shots. It must be the flu. I've caught the flu. He's been in bed with the flu, and missed school today. He came down with the flu.Explanation: Please know that with or without the article (The) are both correct. American like using articles to give emphasis to it. While in British English, it's not necessary to use an article (THE).
I've got flu so I missed school.（インフルエンザで学校を休んだ）
I cached the flu that's why I missed school.（インフルエンザにかかったので学校を休んだ）
I caught flu and missed school.（インフルエンザにかかって学校を休んだ）
Jenny has the flu so she missed school.（ジェニーはインフルエンザで学校を休んだ）
She had flu shots.（彼女はインフルエンザの予防接種を受けた）
It must be the flu.（これはインフルエンザに違いない）
I've caught the flu.（インフルエンザにかかった）
He's been in bed with the flu, and missed school today.（彼はインフルエンザで寝込んでいて、今日は学校を休んだ）
He came down with the flu.（彼はインフルエンザにかかった）
解説：
冠詞の "the" はあってもなくても正解です。アメリカ人は強調のために冠詞を使うことが多いです。一方、イギリス英語では、"the" は不要です。
I had to absent myself from school because I was bedridden with the flu.
I missed a few days of school because I was down with the flu.
1. I had to absent myself from school because I was
bedridden with the flu. To absent yourself means to stay
away from a meeting/event/school/place of work, etc.
Another example: "I absented myself from the meeting
because I had a deadline to meet/project to complete."
"Being bedridden" means that you were so sick to the extent
that you had to remain in bed in order to fully recover.
2. I missed a few days of school because I was down with the flu.
To miss school means being absent or out of school.
Being down with the flu means being confined to your bed
because you were too weak to get up.
1. I had to absent myself from school because I was bedridden with the flu.（インフルエンザで寝込んでいたので、学校を休みました）
"To absent yourself" は「（会合／イベント／学校／会社などを）休む」という意味です。
例：
"I absented myself from the meeting because I had a deadline to meet/project to complete."
（他に締切の近い仕事［終わらせないといけない仕事］があったので、会合を欠席しました）
"Being bedridden" は「病気で寝たきりになって」という意味です。
2. I missed a few days of school because I was down with the flu.（インフルエンザにかかって、数日学校を休みました）
"Being down with the flu" は「インフルエンザで寝込んでいる」という意味です。
I was absent from school today because I had the flu.
I missed class today due to having the flu.
I was sick, so I stayed away from school.
Contracting the flu is a common experience that happens to most of us at some point in our lives. Depending on how sick webecome, we may choose to say away from work or school and vist the doctor or hospital.
If you want to express that you were sick with the flu and didn't go to school, you can use any of the following sentences:-
1. I was absent from school today because I had the flu.
Example: A"I did not see you in class today, were you there?"
B " I was absent from school today becasue I had the flu."
2. I missed class today due to having the flu.
Example A: "Why did you miss class today?"
B:"I missed class today due to having the flu."
3. I was sick, so I stayed away from school.
Example A: "Jenny, I didn't see you for our school test today"
B: "I know, I was sick so I stayed away from school.
インフルエンザにかかることは人生のどこかでほとんどの人に起こることです。どれくらい具合が悪くなるかにもよりますが、 away from workやschool（仕事、学校を休む）や vist the doctor や hospital（医者に診てもらう、病院に行く）というフレーズを使います。
1. I was absent from school today because I had the flu.
（インフルエンザにかかったので、今日は学校を休みました。）
例：
A"I did not see you in class today, were you there?"
（今日クラスで見なかったけど、いた？）
B " I was absent from school today becasue I had the flu."
（インフルエンザにかかったから、今日学校を休んだんだ。）
2. I missed class today due to having the flu.
（インフルエンザにかかったため今日授業を休みました。）
例
A: "Why did you miss class today?"
（どうして今日授業を休んだの？）
B:"I missed class today due to having the flu."
（インフルエンザにかかったから休んだんだ。）
3. I was sick, so I stayed away from school.
（風邪をひいたから、学校を休みました。）
例：
A: "Jenny, I didn't see you for our school test today"
（ジェニー、今日学校のテストで見なかったよ。）
B: "I know, I was sick so I stayed away from school.
（そうなんだ、風邪をひいて学校を休んだんだ。）
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