现在完成时入门——have/has + 过去分词
一、现在完成时的基本结构
肯定句
主语 + have/has + 过去分词 + 其他
- I have finished my homework. (我完成了作业。)
- She has visited Beijing. (她去过北京。)
否定句
主语 + have/has + not + 过去分词 + 其他
- I have not (haven't) finished my homework.
- She has not (hasn't) visited Beijing.
一般疑问句
Have/Has + 主语 + 过去分词 + 其他?
- Have you finished your homework? — Yes, I have. / No, I haven't.
- Has she visited Beijing? — Yes, she has. / No, she hasn't.
二、什么时候用现在完成时？
用法1：表示过去发生的事对现在有影响
强调"结果"或"影响"，而不是"什么时候做的"
例句：I have lost my key. (我把钥匙丢了。→ 现在找不到钥匙了，进不了门) 对比：I lost my key yesterday. (我昨天丢了钥匙。——只陈述过去的事，不强调现在的影响)
用法2：表示"曾经"或"从未"经历过
强调"有没有这种经历"
例句： - I have been to Shanghai. (我去过上海。) - She has never eaten sushi. (她从未吃过寿司。) - Have you ever seen a panda? (你见过熊猫吗？)
用法3：表示从过去一直持续到现在的动作或状态
常与for + 时间段 或 since + 时间点 连用
例句： - He has lived here for five years. (他住在这里五年了。) - They have studied English since 2020. (他们从2020年开始学英语。)
三、规则动词的过去分词变化
规则变化口诀
一般情况下加 -ed：work → worked, play → played 以e结尾加 -d：like → liked, dance → danced 辅音+y变i加 -ed：study → studied, carry → carried 重读闭音节双写尾字母加 -ed：stop → stopped, plan → planned
四、常见不规则动词过去分词（一定要背！）
| 原形 | 过去分词 | 原形 | 过去分词 |
|---|---|---|---|
| be | been | do | done |
| have | had | go | gone |
| see | seen | eat | eaten |
| take | taken | write | written |
| buy | bought | read | read(读音不同) |
| make | made | give | given |
五、现在完成时 vs 一般过去时
| 对比项 | 现在完成时 | 一般过去时 |
|---|---|---|
| 侧重点 | 现在的结果/影响 | 过去的事实 |
| 时间词 | ever, never, already, yet, just, for, since | 具体过去时间 (yesterday, last week, in 2022) |
| 结构 | have/has + 过去分词 | 动词过去式 |
例题：选择正确答案 A: __ you _ (see) the new movie? B: Yes, I ___ (see) it yesterday.
答案： A: Have you seen the new movie? (问有没有看过——现在完成时) B: Yes, I saw it yesterday. (昨天看的——有具体过去时间，用一般过去时)
六、标志词记忆歌
现在完成时标志词： 刚(just)已(already)经，还(yet)未曾(never) 已(already)经做，还(yet)没做 曾经(ever)问，从未(never)答 自从(since)来，为了(for)去
七、实用小技巧
- already vs yet：already 用于肯定句（已经），yet 用于否定句（还）和疑问句（已经）
- been to vs gone to：have been to 去过（已回来），have gone to 去了（还没回来）
- ever 只用于疑问句和否定句："Have you ever..." / "No one has ever..."
- 看到 yesterday, last night, in 2020, just now 等具体过去时间 → 用一般过去时
- 看到 already, yet, ever, never, just, for, since → 用现在完成时
八、练习
-
用 have/has + 过去分词填空： (1) I __ already _ (finish) my homework. (2) She never (be) to the Great Wall. (3) you ___ (see) this film before?
-
改错： (1) I have went to the park yesterday. (2) She has not finish her homework yet. (3) They have saw the movie already.