精品文档---下载后可任意编辑一般现在时 一般现在时的定义：表示常常性的事情，常常性的动作或一般性事实。 一般现在时的标志词：often 常常，usually 通常，always 总是，every每个，sometimes 有时 一般现在时的结构：只有在主语是第三人称单数时动词发生“三单变化”，其他用动词的原形。 三单变化：1.多数在动词后＋s???? play — plays? like — likes （1）直接在动词词尾加-s. ask---asks???? work---works? get---gets????? stay---stays （2）以字母 s, x, ch, sh 或 o 结尾的动词，在词尾直接加-es. watch---watches?? wish---wishes? fix---fixes???????? do---does go---goes???????? pass---passes （3）以“辅音字母加 - y”结尾的动词，要先变 y 为 i 再加-es. try---tries???? study---studies cry---cries????? fly---flies 2.不规则变化： be---- is? are??? have----has 二、一般现在时用法 1. 表示常常性，习惯性 ,永久性的动作或存在的状态 .通常与副词sometimes, often, usually, always, every day (year, month ), once (twice, three times) a day,等时间状语连用。 They usually go to school by bike. I take the medicine three times a day. She helps her mother once a week. Mary’s father is a policeman. There are 50 students in my class. 2. 表示客观真理，科学原理，自然现象，等客观事实或格言，谚语等。精品文档---下载后可任意编辑 ? The sun rises in the east and sets in the west every day. ? The man who has never been to the Great Wall is not a real man. ? Tomorrow is Tuesday. 三、一般现在时的句子转换： （ 1）当句子中有 be 动词或情态动词时，则把 be 动词或情态动词(can,could 等等)提到主语的前面变成疑问句;在 be 动词或情态动词后面加 not变成否定句. 例：①陈述句：She is a student. 疑问句→ Is she a student? 否定句→ She is not a student. ②陈述句：I can swim. 疑问句→ Can you swim 否定句→ I can not swim. （2）?? 当句子中即没有 be 动词，也没有情态动词时，则在主语前加助动词 do (you,以及复数), does（单数 she,he,it）变成问句；在主语后谓语动词前加助动词...
