助动词do, does, did
英语中经常因为人称的关系,动词就有变化。这和中文不同。
最常听的如:你吃饭了吗?
他吃饭了吗? 动词“吃饭”的形式都没有变化的。
而英语就有人称和数的变化。
助动词do, does, did 常用于疑问和否定句,当然也可用于动词原形前面作为强调。Do, does 的时态为“一般现在时”,did 用于“一般过去时”。
1. DO 用于第一、二人称 you 和 复数。
eg. Do you like football?Yes, I do.
They don't (do not) like basketball.
2. DOES 用于第三人称单数 (he, it, she, etc.)
eg. She doesn't (does not) have a brother.
Does it take a long time?
The boy doesn't go to school yet.
3. DID 用在“一般过去时”的句子中,没有人称的变化。
Did you / she/ he / they see the movie?
We/ He/ They didn't have dinner yet.
4. 用于强调。
I do believe you. 我肯定相信你。
They did visit there before. 他们确实去过那里。