Many students study hard every day.

many students 后面加动词原形还是单三？

many students意为“许多学生”，表示复数，所以谓语动词用原形。例如：Many students often play games on the playground. 许多学生经常在操场上做游戏。

如果主语是第三人称单数（如he, she, my father, Tom, his friend, Shanghai, the Great Wall等），那么谓语动词要用第三人称单数形式。例如：

He comes from Australia. 他来自澳大利亚。