四级作文字数不足可通过 “结构化填充 + 细节拓展” 解决，核心扩写技巧包括：开头补充背景引入论点，主体段以 “分论点 + 解释 + 例子” 延伸，将抽象表述具象化，用过渡词衔接逻辑，结尾升华主题并补充建议。这些技巧不堆砌废话，既能自然增加篇幅，又能提升文章逻辑与内容质量，帮助考生在不跑题的前提下满足字数要求。

　　一、核心结论

　　四级作文字数不够，核心是通过 “结构化填充 + 细节拓展” 扩写，既不跑题又能自然增加篇幅，以下是实用技巧。

　　二、高效扩写技巧

　　1. 开头段：补充背景 / 现象引入

　　不直接亮观点，先描述题目相关的社会现象、生活场景，再引出论点。

　　示例：题目 “Online Learning”，可先写 “With the development of digital technology, online learning has gradually become a common way for students to acquire knowledge, especially when they cannot attend offline classes.”

　　2. 主体段：分论点 +“解释 + 例子” 双拓展

　　每个分论点后，先解释论点的合理性(“为什么这样说”)，再补充具体例子(个人经历、社会案例、简单数据)。

　　示例：论点 “Online learning is flexible”，可扩写为 “Online learning allows learners to arrange study time according to their own schedules. For example, college students can watch lecture videos after finishing daily courses, and office workers can study during their spare time on weekends. This flexibility helps people balance study and other responsibilities.”

　　3. 细节具象化：用具体表述替代空泛词汇

　　把抽象形容词、名词转化为具体场景、动作或感受，避免重复简单表达。

　　示例：将 “many people like it” 改为 “a large number of students and professionals are in favor of online learning, as it saves them the time spent on commuting and provides more learning resources.”

　　4. 逻辑衔接：添加过渡句 / 补充说明

　　段落间用 “besides”“in addition”“furthermore” 衔接，论点内用 “in fact”“specifically”“for instance” 补充，既凑字数又显逻辑。

　　示例：写完一个分论点后，加 “Besides the flexibility mentioned above, online learning also has the advantage of rich learning resources.”

　　5. 结尾段：升华主题 + 补充建议 / 展望

　　不只是简单总结，可添加对未来的展望、具体建议或强调现实意义。

　　示例：结尾可写 “To make online learning more effective, learners should improve self-discipline and choose high-quality courses. In the future, online learning is likely to combine with more advanced technologies, bringing better learning experiences to people.”