Your friend would not understand _____ you are going through.

What 引导的宾语从句 扩展：what 引导的其他名词性从句，一起到连接词或引导词的作用；二，在从句中充当一定的成分，主语、宾语、表语、定语。 We should make use of spare time to study. — What use should be made of spare time to study? — You should know _____ use should be made of spare time to study.

what

what