My grandfather (goes) to the park every morning.
They are (having) a lesson now.
The teacher is (standing) in front of the blackboard.
He (painted) his desk black last week.
I （have) already (finished) my work
若有任何疑问可以【直接回复】或是【继续追问】或是【百度hi】我
尽量在最短的时间内回复第一个为什么是goes呢My grandfather 是第三人称，后面的动词要用第三人称单数