Only when he reached the tea-house did he realize it was the same place he'd been in last year.

问题描述:

Only when he reached the tea-house did he realize it was the same place he'd been in last year.
为什么这里的realize不用过去式呢?

因为前面是only when 引导的部分倒装,已经有了助动词did了,所以后面用动词原形realise