Gerund phrase / To-infinitive phrase + singular verb + complement. 或 It + be + adjective/noun + to-infinitive phrase.
PTE 高频程度
High
AI 学习推荐
Core Grammar
适用考试
PTE / IELTS
语法结构
Grammar Structure
结构公式
Gerund phrase / To-infinitive phrase + singular verb + complement. 或 It + be + adjective/noun + to-infinitive phrase.
当一个动作或行为本身成为句子的讨论对象时，可以使用非谓语结构作主语。Gerund phrase 通常由 V-ing 开头，可带宾语、状语或被动形式，如 reducing carbon emissions、being exposed to noise。To-infinitive phrase 由 to + base verb 构成，如 to address inequality、to improve public transport。二者作主语时，整个短语相当于一个名词性成分，谓语动词通常用单数。若主语部分较长，学术英语更倾向于使用 it 作形式主语，例如 It is essential to evaluate the evidence carefully.
Reducing air pollution requires coordinated action from governments and individuals.
减少空气污染需要政府和个人的协调行动。
To ignore the long-term effects of climate change is irresponsible.
忽视气候变化的长期影响是不负责任的。
It is important to distinguish correlation from causation in academic research.
❌ To improving public health requires long-term investment.
Correct
✅ Improving public health requires long-term investment.
to 后面不能接 V-ing 作不定式结构。可以用 gerund 作主语：Improving public health；也可以说 To improve public health, governments need long-term investment，但这时 to improve 是目的状语，不是主语。
Incorrect
❌ Reducing waste are beneficial to the environment.
Correct
✅ Reducing waste is beneficial to the environment.
❌ It is important improving students' critical thinking.
Correct
✅ It is important to improve students' critical thinking.
在 It is + adjective 结构中，后面通常接 to-infinitive，而不是直接接 V-ing。正确结构是 It is important to do something。
Incorrect
❌ To protect the environment is depend on public awareness.
Correct
✅ Protecting the environment depends on public awareness.
depend 是实义动词，不能与 is 同时作谓语。句子主语可用 gerund：Protecting the environment；谓语用 depends。
Incorrect
❌ Being improve education quality is a major priority.
Correct
✅ Improving education quality is a major priority.
being 后面不能接动词原形 improve。若表示主动行为，应使用 gerund：Improving education quality；若表示被动，应为 being improved，但此处语义不适合。
学术表达
Academic Patterns
Doing something is essential for achieving something.
做某事对于实现某目标是必要的。
Doing something plays a significant role in something.
做某事在某方面发挥重要作用。
Doing something requires careful consideration of multiple factors.
做某事需要仔细考虑多个因素。
To address this issue, it is necessary to do something.
为了解决这个问题，有必要做某事。
To assume that something is always true would be misleading.
假设某事总是正确的会产生误导。
It is crucial to evaluate the evidence before reaching a conclusion.
在得出结论之前，评估证据至关重要。
It is difficult to determine whether this trend is beneficial in the long term.
很难判断这一趋势从长远来看是否有益。
Being exposed to something may have long-term consequences.
接触某事物可能会产生长期后果。
PTE 高频应用
PTE Usage
非谓语作主语在 PTE Academic 中出现频率较高，尤其体现在写作和阅读中的长句理解。PTE 评分关注语法准确性、句子结构多样性和表达的正式程度。使用 gerund 或 to-infinitive 作主语可以帮助考生构造更成熟的学术句式，例如 Reducing income inequality is essential for social stability. 在 Summarize Written Text 中，该结构有助于压缩信息；在 Write Essay 中，它能作为主题句或论证句；在 Reading & Writing: Fill in the Blanks 中，考生需要根据句法位置判断应选择 V-ing、to do 还是谓语动词形式。
Summarize Written Text
Write Essay
Reading & Writing: Fill in the Blanks
Reading: Fill in the Blanks
Read Aloud
Highlight Incorrect Words
高频搭配
Common Collocations
improving public health
改善公共健康
reducing carbon emissions
减少碳排放
addressing social inequality
解决社会不平等问题
promoting economic growth
促进经济增长
enhancing students' critical thinking
提升学生的批判性思维
protecting personal privacy
保护个人隐私
being exposed to harmful content
接触有害内容
to evaluate the available evidence
评估现有证据
to maintain social stability
维持社会稳定
to achieve sustainable development
实现可持续发展
AI 学习建议
AI Learning Tips
写作时如果句子开头是一个动作概念，优先考虑使用 V-ing 作主语，例如 Reducing waste is more practical than banning all plastic products.
如果想表达目的或评价某个行为，可使用 It is + adjective + to do，使句子更自然，例如 It is unreasonable to ignore the needs of low-income families.
检查非谓语作主语的句子时，先找到真正的谓语动词。不要把句首的 V-ing 或 to do 误判为谓语。
在 PTE 写作中，非谓语作主语适合用作主题句，但不要连续多句都用同一种开头，否则句式会显得单一。
遇到 Reading Fill in the Blanks 时，如果空格位于句首且后面已有谓语动词，答案很可能需要名词、gerund 或 to-infinitive，而不是过去式或第三人称单数谓语。
AI 练习题
Practice Questions
选择正确形式填空：_____ renewable energy can reduce dependence on fossil fuels. (Use / Using / Used)
答案：Using renewable energy can reduce dependence on fossil fuels. 解释：句首作主语，应使用 gerund：Using。
改正错误：To learning a second language requires patience and consistent practice.
答案：Learning a second language requires patience and consistent practice. 解释：to 后不能接 learning 构成不定式；此处应用 gerund 作主语。
改写句子，使用形式主语 it：To assess the reliability of the data is essential.
答案：It is essential to assess the reliability of the data. 解释：用 it 作形式主语可以让句子更自然，真正的主语 to assess the reliability of the data 放在句末。
选择正确谓语：Protecting endangered species _____ a global responsibility. (is / are)
答案：Protecting endangered species is a global responsibility. 解释：gerund phrase 作主语时整体视为单数，所以用 is。
将中文翻译成英文：提高教育质量需要政府、学校和家庭的合作。
答案：Improving the quality of education requires cooperation among governments, schools and families.
判断并改正：It is necessary reducing the cost of public transport.
答案：It is necessary to reduce the cost of public transport. 解释：It is necessary 后通常接 to-infinitive。
用非谓语作主语完成句子：_____ may widen the gap between urban and rural students. 提示：过度依赖在线教育
答案：Relying excessively on online education may widen the gap between urban and rural students.
选择更适合学术写作的句子：A. People should improve public awareness is important. B. Improving public awareness is important.
答案：B. Improving public awareness is important. 解释：A 句结构错误，People should improve public awareness 是完整分句，不能直接作主语；B 句使用 gerund phrase 作主语，结构正确。
