I wish it was like this more frequently.一定要用was?

题目

I wish it was like this more frequently.一定要用was?
One:"Hi Mary."
Two:"Oh,hi."
One:"How are you doing?"
Two:"I’m doing alright.How about you?"
One:"Not too bad.The weather is great isn’t it?"
Two:"Yes.It’s absolutely beautiful today."
One:"I wish it was like this more frequently."
最后1句里的was,帮我讲下语法

答案

wish 后面是虚拟语气,必须用be的过去时,这里主语是it,所以用was