I went to high school with the principal of this school.
The principal of this school was my classmate in high school.
「この学校の校長先生は私の高校時代の同級生です。」には色々な言い方があります。
英語的な発想だと「一緒に高校に行った」と考え、「I went to high school with the principal of this school.」などと伝えることができます。「高校時代の同級生」を直接反映させるなら「The principal of this school was my classmate in high school.」と言っても良いでしょう。
ちなみに、イギリス英語では高校を「college」と呼ぶことがあり、私の住むニュージーランドでは「high school」も「college」も同じ意味です。
I was in the same class with the principal of this school.
We both went to high school together.
*I was in the same class with the principal of this school.
This means you were classmates and this means you are probably the same age.
*We both went to high school together.
You can use this sentence if the person you are talking to knows about the person you talking about.
*（英文）I was in the same class with the principal of this school.
（訳）私はこの学校の校長と同じクラスでした。
これはクラスメイトで同世代だという意味です。
*（英文）We both went to high school today.
（訳）私たちは二人とも一緒に高校へ行きました。
相手があなたが話している人のことを知っていたらこの文を使えます。
back in (a time/year/period of time) - you can use this to describe something you used to do during a certain time period
A. I was once very famous, you know.
B. Yeah, when?
A. Back in the 90's, I was in a very famous tv show.
B. What was it called then?
A. "Horsin' Around"
B. Well, I've never heard of it.
back in (a time/year/period of time) - 昔一時的にしていた事
（英訳）
A. I was once very famous, you know.
B. Yeah, when?
A. Back in the 90's, I was in a very famous tv show.
B. What was it called then?
A. "Horsin' Around"
B. Well, I've never heard of it.
（訳）
A. 昔、私にも有名だった時期があったんだよ
B. いつ？
A. ９０年代の頃、有名な番組に出演してました
B. なんて番組？
A. "Horsin' Around"
B. 聞いた事ないわ
As a student I rubbed shoulders with the principal
The most straightforward way of mentioning that you went to school with the principal is to say that you were in the same class. If you rub shoulders with someone at a specific time in your past, then you were with that person at that time - possibly as friends, but possibly also in other roles such as workmates, or just acquaintances who spent time together for some reason.
To rub shoulders with someone - to meet and spend time with someone:
"She claims that she rubs shoulders with royalty all the time."
校長先生と学校に行ったことを言うもっとも直接的な方法は、同じクラスにいたと、言うことです。
もし、過去の特定の時刻に誰かと一緒にいたのであれば、そのときにその人と were with と言うことができます。
おそらく、友達や同僚、同じ理由で一緒に過ごした仲間として。
誰かと rub shoulders ということは、誰かと会って一緒に過ごしたということです。
She claims that she rubs shoulders with royalty all the time.
彼女は常に王族と交際していると主張しています。
I went to high school with the principal of this school
I attended the same high school as the principal of this school
The principal of this school went to/attended the same high school as me
If you are talking about going to/has been to then you can use the terms 'went to' or 'attended'
you could also say 'we both attended/went to the same high school' if they know the person you are talking about
「～に行った [通った]」は、'went to'や'attended'で表せます。
また、聞き手が誰について言っているか分かる場合には、
'We both attended/went to the same high school'（私たちは同じ高校に行っていました）
と言ってもいいです。
The principal of this school went to high school with me.
The principal of this school and I went to high school together.
Native speakers will say like this: “The principal of this school and I went to high school together”.
There are lots of other ways to say it, but this one is the most accurate and most commonly used.
Here is an example on how to use this in a conversation:
A: The principal of this school and I went to high school together.
B: What an interesting turn of fates!
ネイティブスピーカーは次のように言います。
“The principal of this school and I went to high school together”.
（この学校の校長は私の高校の同級生です）
他にもいろいろな言い方ができますが、これが最も正確で一般的です。
会話では以下のように使えます。
A: The principal of this school and I went to high school together.（この学校の校長は私の高校の同級生です）
B: What an interesting turn of fates!（面白い運命の巡り合わせですね）
The principal of the school used to be my old schoolmate.
The principal and I used to go to high school together.
I went to high school with the current principal.
If the person already knows which school you are referring to, then you can just say 'this school' or 'the school'. If you belonged to the same class or classes as the current principal, then you can say, "We went to high school together." This does not mean you were friends but that you attended the same school at the same time. In this case, we use 'schoolmate' to refer to a person you attended school with, even if you were not friends or if you were not in the same class.
もし相手がどの学校について言っているか分かるなら、単に'this school'や'the school'と言えます。
もし現在の校長と同じクラスだったということなら、"We went to high school together"と言えます。これは「友達だった」という意味ではなく「同じ時期に同じ学校に通った」という意味です。
この場合、'schoolmate'は「〔友達や同じクラスでなくても〕同じ学校に通った人」という意味です。
日本 
南アフリカ 
アメリカ合衆国 
イギリス 
カナダ 
