when I was in high school
Eu li este livro quando estava no ensino médio.
I read this book when I was in high school.
Tom me disse que ele costumava tocar clarinete quando estava no ensino médio.
Tom told me that he used to play the clarinet when he was in high school.
Tive que estudar francês quando estava no ensino médio.
I had to study French when I was in high school.
Eu estudei francês quando estava no ensino médio.
I studied French when I was in high school.