It'salwayspleasanttodowhatyou'regoodatdoing.做自己擅长的事总是令人愉快的.todowhatyou'regoodatdoing是真主语,缩合关系代词what=thethingthat,that在从句中作动名词短语的宾语,at+动名词短语作

Question

It's always pleasant to do what you're good at doing.
做自己擅长的事总是令人愉快的.
to do what you're good at doing是真主语,缩合关系代词 what = the thing that,that在从句中作动名词短语的宾语,at + 动名词短语作什么类型的状语呀 you're good 是系表结构?

Answer 1

划分句子成分有助于解决你的问题：
【It 形式主语 】【is谓语 】always 【pleasant表语】【 to do what you're good at doing不定式短语,真主语】.
不定式短语成分：
【to do 动词不定式】【 what you're good at doing 宾语从句】
宾语从句成分：
【 what 做后面doing的宾语】【you主语 】【are good at 形容词短语,谓语】【doing 介词宾语】
be good at 固定形容词短语,一般看做整体,很少分开来.
祝你开心如意!