现在完成时是have/has started

已经开始

My youngest child is eight and she has started answering back too.

我最小的孩子8岁,也已经开始顶嘴了。

In Bangladesh, the monsoons have started.

在孟加拉国,雨季已经开始。

Start to choose a hobby .

开始选择一项爱好。

Then I start to panic .

之后我就开始惊慌。