【求英语语法现在完成时讲解,例子,习题(附答案)】现在完成时是英语中非常重要的时态之一，常用于表达过去发生的动作对现在的影响或与现在有关联。它由“助动词have/has + 过去分词”构成。下面将从定义、结构、用法、例句以及练习题等方面进行总结。
一、现在完成时的结构
| 主语 | 助动词 | 过去分词 | 例句 |
| I/We/They/You | have | done | I have finished my homework. |
| He/She/It | has | done | She has gone to school. |
二、现在完成时的用法
| 用法 | 说明 | 例句 |
| 表示过去某一动作对现在的影响 | 强调过去的动作对现在的影响 | I have lost my key. (我现在没有钥匙) |
| 表示从过去某一时间持续到现在的动作 | 常与“for”或“since”连用 | They have lived here for five years. |
| 表示经历（尚未完成） | 表示某人曾经做过某事，但不强调具体时间 | Have you ever been to Paris? |
| 表示刚刚完成的动作 | 通常和“just”、“already”等副词连用 | He has just arrived. |
三、常见动词的过去分词形式
| 动词原形 | 过去分词 | 说明 |
| go | gone | 不规则变化 |
| have | had | 不规则变化 |
| do | done | 不规则变化 |
| eat | eaten | 不规则变化 |
| write | written | 不规则变化 |
| study | studied | 规则变化 |
| play | played | 规则变化 |
| watch | watched | 规则变化 |
四、现在完成时的常见错误
1. 混淆一般过去时和现在完成时
- ❌ I went to the store yesterday.
- ✅ I have gone to the store. （表示现在已不在商店）
2. 误用时间状语
- ❌ I have lived here since 2010.（正确）
- ❌ I have lived here for 2010.（错误，应为“since 2010”）
3. 忘记使用过去分词
- ❌ I have go to school.
- ✅ I have gone to school.
五、练习题（附答案）
一、选择正确的时态填空：
1. She ______ (go) to the library already.
答案：has gone
2. We ______ (not finish) our project yet.
答案：have not finished
3. He ______ (live) in London for three years.
答案：has lived
4. They ______ (eat) dinner when I called.
答案：had eaten（注意：这里应使用过去完成时）
5. I ______ (lose) my phone. Can you help me find it?
答案：have lost
二、翻译句子：
1. 我已经吃过晚饭了。
答案：I have had dinner.
2. 他从未去过日本。
答案：He has never been to Japan.
3. 我们已经等了两个小时。
答案：We have been waiting for two hours.
4. 她刚收到一封电子邮件。
答案：She has just received an email.
5. 他们已经完成了作业。
答案：They have finished their homework.
通过以上讲解、例句和练习题，可以更清晰地掌握现在完成时的用法和结构。建议多做相关练习，以提高语言运用能力。
