yesterday

It rained heavily yesterday, so the ground is still very muddy today.

(Chinese) 昨天下了大雨，所以今天地面仍然很泥泞。

I met my old high school teacher at the supermarket yesterday morning.

(Chinese) 昨天早上我在超市遇到了我的高中老师。

Today's technology makes the computers of yesterday look like toys.

(Chinese) 今天的技术让昨天的电脑看起来像玩具。

We shouldn't dwell on our yesterdays; we must focus on the future.

(Chinese) 我们不应沉溺于往昔，而必须专注于未来。