study的过去式是studied。以下是“study”的过去式“studied”的例子：
I studied for three hours last night before the exam.
(昨晚我为了考试学习了三个小时。)
They studied the report carefully before making a decision.
(他们在做出决定之前仔细研究了报告。)
We studied together in the library every day last semester.
(上个学期我们每天一起在图书馆学习。)
He studied abroad for two years and learned a lot.
(他在国外学习了两年，学到了很多。)
She studied hard for the piano exam and passed with flying colors.
(她为钢琴考试努力学习，最终取得了优异的成绩。)
在这些例子中，“studied”是动词“study”的过去式，用于描述过去发生的学习行为或状态。
