only to 是表示很遗憾地发现.一般后面跟上不好的事情.
比如,I rush to the railway station,only to find the train has gone.
only to 和although 都是连词,也不是说不能用,比如,你可以说,
I rush to the railway station,only to find the train has gone,although I have done my best.多一个连词,就要多一个相应的动词或动词短语,但这种表达让人感觉很累赘,所以一般不这么用.