高中英语核心语法专项：be certain与be sure用法完全指南

在高中英语语法体系中，be certain和be sure的用法区别是历年高考的重点考查内容。本文通过典型例句解析、易混淆点对比、实战应用训练三个维度，系统梳理这两个表达的核心使用规则。

核心用法对比解析

对比维度	be certain	be sure
主语从句适用性	It is certain that...	不适用主语从句结构
语气强度	客观确定性更高	主观确信性为主
否定形式	be uncertain about	be not sure of

典型应用场景分析

场景一：客观事实陈述

✓ It is certain that global warming will cause sea levels to rise.
✗ ~~It is sure that...~~（错误用法）

场景二：主观判断表达

✓ I'm sure we've made the right decision based on current data.
✓ We're certain about the accuracy of the experiment results.

进阶应用训练

易错点警示：注意介词搭配差异

✓ They were certain of winning the championship
✓ She wasn't sure about the meeting schedule
✗ ~~He's certain for~~ the answer（错误搭配）

实战改错练习

1. It's sure that the conference will be postponed.
修正：It's certain that...

2. Are you certain with the delivery time?
修正：Are you certain about...

关联知识点拓展

对比记忆：be familiar with/to 的用法区别
✓ 主动掌握：familiar with（主体是人）
✓ 被动熟悉：familiar to（主体是物）
例证：The operating system is familiar to most users.
Most users are familiar with the operating system.