现在完成时强调"过去的动作对现在的影响"，或从过去持续到现在的状态。
◆ 结构：have / has + 过去分词
· I have finished my homework.（我已经写完作业了——现在可以玩了。）
· She has lived in Nanning for ten years.（她在南宁住了十年了——现在还住着。）
◆ 常考标志词
· already（已经）、yet（还，用于否定/疑问）、just（刚刚）、ever（曾经）、never（从未）
· for + 时间段：for two years since + 时间点：since 2020 / since last year
◆ 中考高频考点
1. have been to（去过，已回来）vs have gone to（去了，还没回来）：
He has been to Beijing twice.（他去过北京两次。）
He has gone to Beijing.（他去北京了，人不在这儿。）
2. 瞬间动词（buy, join, die, come...）不能与 for/since 时间段连用，要转换：
He has bought the book ✗ for two days
→ He has had the book for two days.（buy → have）
→ He has been in the club since 2023.（join → be in）