估计你是弄反了，应该是 amazed at，即 at 在 amazed 之后。即：

If you live here or visit the city often, you will be amazed at how everything is being changed so quickly.

类似的例子如：

I never cease to be amazed at the way people hurt one another. 人们互相伤害的方式令我惊讶不已。

You’d be amazed at how much she spends on clothes. 你要是知道她花多少钱购置服装，会大吃一惊的。

You’ll be amazed at the culinary creations possible in a Dutch oven. 荷兰烤箱能够做的食物之多会让你感到惊奇。