The man ____ you are going to make friends is my father’s neighbour.

The man ____ you are going to make friends is my father’s neighbour.

with whom
首先我们来分析一下句子，句子的主干是：The man is my father's neighbour.
you are going to make friends是the man 的定语。这里需要一个关系词。
短语make friends with sb,先行词又是指人又做with的宾语所以用whom

with whom

that应该是同位语从句吧 再看看别人怎么说的。

who 或者that.... (*^__^*) ……

这是个同谓语从句，可以用三种：1.that ，2.介词＋whom/which，本题为with whom或者that，第三种由于久疏战场，难以记起，惭愧！

楼上正解 with whom 1因为后面带的从句变成完整句子应该是you are going to make friends with the man.所以要有with 这是固定搭配 2the man 是宾语，所以要用whom