为了帮助大家顺利通过考试,英语四六级考试栏目大家准备了大学英语CET6考试(语法)备考精讲的资料供大家学习,希望会对大家有所帮助,欢迎大家前来我站学习。预祝大家考试顺利。
用法辨异
1. can/be able to
1) can 只有两种时态形式,现在时和过去时,而 be able to 有多种时态形式。如:
Mary can play cards. She has been able to do it since she was 8 years old.
玛丽会打牌。她 8 岁起就会打了。
2) 用在过去时中,could 经常表示能够做某事,事实上不一定去做,而 was/were able to 则表示“过去做
成了某事”。在否定句中两者可通用。如:
He could swim across the river. But he didn’t feel like it that day.
他能游过那条河,但那天他不想游。
Yesterday I was able to get home before the heavy rain. 昨天我在下大雨前赶到了家里。
2. would/used to
1) used to 表示过去与现在或过去某时与后来的情况有不同,而 would 只表过去的情况。如:
People used to think that the sun moved around the earth.
过去人们认为太阳围绕地球转。(现在人们不这么认为)
She would go out for a walk in the morning when she lived in the suburb.
在郊区住时,她总是在早晨去散会儿步。(可能现在仍有散步的习惯。)
2) used to 可表示过去的习惯动作和状态,而 would 只表示过去的习惯动作,不表示状态。如:
He used to/would smoke while reading. 过去他在看书时常抽烟。
She used to be very thin. 她过去很瘦。
相关阅读信息推荐: