我要去远方探望我朋友的妈妈，随后我们要去办理结婚手续。

I will go far to see a friend of my mother's and then we will transact marriage procedure.

youdao

然而，我感到非常抱歉，那天我要去探望一个重病的朋友，所以我恐怕没办法陪你去了。

However, I am awfully sorry to tell you that on that day I am going to see an old friend who's seriously ill. So I am afraid it's impossible for me to go with you then.

youdao