错误1：用 ago
× I have seen him two days ago.
✓ I saw him two days ago.
口诀： Ago 别跟完成时跑，一般过去时才是它老相好。
错误2：用 yesterday/last week 等具体过去时间
× She has finished her homework yesterday.
✓ She finished her homework yesterday.
套路句式： 看见 yesterday/last/具体日期，现在完成时就赶紧换一般过去时。
错误3：since 和 for 搞混
× I have lived here since three years.
✓ I have lived here for three years.
✓ I have lived here since 2021 / since I was a child.
口诀： Since 后接“时间点”，年份、从句或短语；For 后面跟“时间段”，数字加 years/hours 看得见。
错误4：already/yet 位置错
× I have yet finished my work. (yet 放中间错)
✓ I have already finished my work.
✓ I have not finished my work yet.
✓ Have you finished your work yet?
套路句式： Already 肯定句中夹，yet 疑问否定末尾挂。
高频考点时间状语清单：
对（常用）： recently, lately, so far, up to now, in the past few years, already, yet, just, ever, never, since + 点, for + 段
错（禁用）： ago, yesterday, last week/month, in 1990, at that time