虚拟语气问题the food and drinks were great,but if only we had know

Answer:
笔者从三个层面来解析一下问题:
1.从"if only"的用法上
if only 译为:要是..多好 引导虚拟条件句通常独立使用,没有主句.
2.从句构上
But是表转折关系的并列连词不可能把主从句分开,由此判断"if only we had known a few of the other guests"就是省略了主句而单独使用的虚拟条件句
译为:要是当时我们能再认识一些其它客人该有多好呀!
这也是为什么句中没出现"would have done"与从句对应该的虚拟时态,因为主句根本就没出现.
3.从时态上
在if only引导的虚拟条件句中,从句用过去完成时态表对过去的虚拟.那么从何处判断是对过去的虚拟呢? 就是并列句的前半句"the food and drinks were great"由"were"可知,这是在陈述过去发生的事情.
为了便于LZ理解,我把此句补成一个完整形式
The food and drinks were great, but if only we had known a few of the other guests,I would have got more help in our business .
祝 学习进步!