主语从句位于句首时，整个从句相当于一个名词性主语。例如 What students need most 表示“学生最需要的东西”，整个从句作主语，后面的 is, remains, matters 等动词通常用单数形式。常见连接词包括：that 表示事实或观点；whether 表示“是否”；what 表示“所……的事物”；who 表示“谁”；why, how, when, where 分别表示原因、方式、时间和地点。由于句首主语从句较长，学术英语中也常使用形式主语 it，把真正的主语从句放到句末，例如 It is evident that online learning has changed education.
What governments should prioritize is the long-term sustainability of public services.
政府应该优先考虑的是公共服务的长期可持续性。
That excessive screen time affects children’s concentration has been widely discussed.
过度使用电子屏幕会影响儿童注意力这一点已经被广泛讨论。
Whether remote work improves productivity depends on the nature of the job.
远程办公是否能提高生产力取决于工作的性质。
It is widely acknowledged that education plays a crucial role in social mobility.
What the speaker emphasizes is the importance of early intervention in public health.
演讲者强调的是公共卫生中早期干预的重要性。
Why this trend has become more common is closely related to technological development.
为什么这一趋势变得更加普遍，与技术发展密切相关。
常见错误
Common Mistakes
Incorrect
❌ What should governments do is reduce pollution.
Correct
✅ What governments should do is reduce pollution.
主语从句中必须使用陈述语序，而不是疑问语序。错误句把 should 放在主语 governments 前，形成了疑问句语序。正确表达应为 What governments should do。
Incorrect
❌ That education is important are undeniable.
Correct
✅ That education is important is undeniable.
整个 that 引导的主语从句作一个整体主语，通常视为单数概念，所以谓语动词应使用 is，而不是 are。
Incorrect
❌ Whether students should use AI tools are still debated.
Correct
✅ Whether students should use AI tools is still debated.
whether 引导的主语从句整体作主语，谓语动词应使用单数形式 is。中国学习者容易被从句内部的复数名词 students 或 tools 干扰。
Incorrect
❌ It is important students develop critical thinking.
Correct
✅ It is important that students develop critical thinking.
在 It is important that... 结构中，that 不应随意省略，尤其在正式写作中应保留，以保证句子结构清晰。
Incorrect
❌ What he said it was convincing.
Correct
✅ What he said was convincing.
What he said 已经是句子的主语，后面不能再加 it 作重复主语。中文常说“他说的话，它很有说服力”，但英文中不能出现双主语。
Incorrect
❌ That whether online education is effective is questionable.
Correct
✅ Whether online education is effective is questionable.
that 和 whether 通常不能同时引导同一个主语从句。若表达“是否有效”，应直接使用 whether。
Incorrect
❌ What is the main problem is the lack of funding.
Correct
✅ What the main problem is is the lack of funding.
主语从句内部要使用陈述语序：the main problem is。句中连续两个 is 是可以接受的，第一个属于从句，第二个是主句谓语，但写作中也可改为 The main problem is the lack of funding 以避免笨重。
学术表达
Academic Patterns
It is widely acknowledged that + 从句
人们普遍认为……
It is evident that + 从句
很明显……
It remains unclear whether + 从句
……是否……仍不清楚
What needs to be emphasized is that + 从句
需要强调的是……
What distinguishes A from B is + 名词 / 名词短语
区分 A 和 B 的是……
Whether + 从句 + depends largely on + 名词
……是否……在很大程度上取决于……
Why this issue matters is that + 从句
这个问题重要的原因在于……
How this problem can be solved remains a major challenge.
如何解决这个问题仍然是一个重大挑战。
That + 从句 + suggests that + 从句
……这一点表明……
It is reasonable to argue that + 从句
有理由认为……
PTE 高频应用
PTE Usage
主语从句在 PTE Academic 中非常实用，尤其适合构建复杂句、提高语法多样性和学术表达质量。在 Write Essay 中，考生可以用 It is widely believed that..., What needs to be considered is..., Whether this policy is effective depends on... 来表达观点和论证。在 Summarize Written Text 中，主语从句有助于压缩信息并突出核心主题。在 Retell Lecture 和 Summarize Spoken Text 中，使用 What the speaker highlights is... 可以准确概括讲座重点。需要注意的是，PTE 评分重视语法准确性，因此主语从句的语序、谓语一致和连接词选择必须正确。
Write Essay
Summarize Written Text
Summarize Spoken Text
Retell Lecture
Answer Short Question
Reading & Writing: Fill in the Blanks
高频搭配
Common Collocations
It is widely believed that
人们普遍认为
It is generally accepted that
人们普遍接受的是
It is worth noting that
值得注意的是
It is essential that
……是至关重要的
It remains uncertain whether
……是否……仍不确定
What matters most is
最重要的是
What needs to be considered is
需要考虑的是
Whether this approach is effective
这种方法是否有效
Why this phenomenon occurs
为什么这种现象会发生
How individuals respond to change
个人如何应对变化
AI 学习建议
AI Learning Tips
写作中如果主语从句超过 8 到 10 个单词，优先考虑使用形式主语 it，例如把 That many young people struggle to find affordable housing is concerning 改为 It is concerning that many young people struggle to find affordable housing。
检查主语从句时，先找连接词，再判断从句内部是否为陈述语序；如果出现 What should people do, Why does it happen 这类疑问语序，通常需要改成 What people should do, Why it happens。
在 PTE Essay 中不要机械重复 It is important that，可以根据语义替换为 It is evident that, It is arguable that, It is crucial that, It remains uncertain whether，以提升语言多样性。
使用 what 引导主语从句时，what 本身通常表示“所……的事物”，后面不能再加 the thing。例如 What society needs is better healthcare，而不是 What the thing society needs is better healthcare。
AI 练习题
Practice Questions
将句子改为主语从句：Governments should invest more in public transport. This is obvious.
答案：It is obvious that governments should invest more in public transport.
选择正确句子：A. Whether online learning is effective depends on students’ discipline. B. Whether is online learning effective depends on students’ discipline.
答案：A 正确。whether 引导的主语从句应使用陈述语序：online learning is effective。
改正错误：What should universities teach is practical knowledge.
答案：What universities should teach is practical knowledge.
用 What matters most is... 造一个关于环境保护的学术句子。
答案：What matters most is whether individuals and governments can take consistent action to reduce carbon emissions.
将中文翻译成英文：人工智能是否会提高工作效率仍然存在争议。
答案：Whether artificial intelligence will improve work efficiency remains controversial.
改正错误：That students need emotional support are often ignored.
答案：That students need emotional support is often ignored.
用形式主语 it 改写：That children are exposed to violent content online is worrying.
答案：It is worrying that children are exposed to violent content online.
