【一般现在时】
1. 一般现在时的基本结构:对于多数主语,动词使用原形,如"I do my homework every day." 对于单数第三人称主语(如Jim),动词需变化为其对应的第三人称单数形式,如"Jim does his homework every day." 动词变第三人称单数时,通常在词尾加-s(清辅音后读/s/,浊辅音后读/z/;t后读/ts/,d后读/dz/)。一些特殊情况如以s,x,ch,sh,o结尾的动词加-es,读作/iz/,如"passes, fixes, teaches, wishes";以辅音字母加y结尾的词,先变y为i,再加-es,读作/z/,如"studies, carries, flies"。特别要注意的是,动词have的第三人称单数形式是has。
2. 一般现在时的用法:
a) 描述习惯性或规律性的动作,常与频度副词如always, often, usually, seldom, never搭配,如"He often goes swimming in summer."
b) 表达当前的状态,如"The boy is twelve."
c) 表示主语的特性、性格或能力,如"My sister is always ready to help others."
d) 描述客观事实、自然现象,如"The earth moves around the sun."
e) 在某些情况下,用一般现在时表示计划中的未来动作,如"The train leaves at six tomorrow morning."
f) 在复合句中,当主句是一般将来时,从句可能用一般现在时代替一般将来时,如时间状语或条件状语从句。
【一般过去时】
1. 一般过去时的基本结构:动词使用其过去式,如"I did my homework yesterday." 不规则动词的过去式需要记忆,如"did"是"do"的过去式。
改写练习:
- "I do my homework every day." 变为一般疑问句是"Do you do your homework every day?" 回答:"Yes, I do." 或 "No, I don't."
- "I do my homework every day." 变为否定句是"I don't do my homework every day."
- "Jim does his homework every day." 变为一般疑问句是"Does Jim do his homework every day?" 回答:"Yes, he does." 或 "No, he doesn't."
- "Jim does his homework every day." 变为否定句是"Jim doesn't do his homework every day."
以上是初中英语动词时态总复习中的重点内容,包括了一般现在时和一般过去时的构成、用法及句子改写。通过掌握这些知识,学生可以更好地理解和运用英语中的不同动词时态,从而提升语言表达的准确性和流畅性。