Question

英语语法问题

, my best friend [to start] for the West to make my fortune, we agreed we would meet here again exactly twenty years from that date and time.这里为什么用to start
Twenty years ago tonight, when I said goodbye to J, my best friend [to start] for the West to make my fortune, we agreed we would meet here again exactly twenty years from that date and time.

Answer 1

这个句子断句是这样的：
My best friend 【to start for West { to make my fortune}】we agreed [we would meet here again exactly twenty years from that date and time.]
句意：我最好的【将出发去西方为我赚钱】 的朋友 ，我们同意（约定）我们将会在从此时此日开始的二十年后在这里相遇。

在这里“to start...."是一个不定式引导的短语，作为定语，补充说明"friend" 的情况。
用不定式“to start...."，说明“将要”发生的情况，现在还没有进行。
而句子后半句的“would ...."是虚拟语气。

Answer 2

不定式t短语做定语修饰前面的my best friend

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那为什么必须用不定式