能具体解释一下什么是一般现在时吗.最好有例子啦.

一般现在时的用法 1) 经常性或习惯性的动作,常与表示频腮度的时间状语连用。 时间状语： every…, sometimes, at…, on Sunday I leave home for school at 7 every morning。2) 客观真理,客观存在,科学事实。 The earth moves around the sun。 Shanghai lies in the east of China。3) 表示格言或警句中。 Pride goes before a fall。 骄者必败。 注意：此用法如果出现在宾语从句中,即使主句是过去时,从句谓语也要用一般现在时。例：Columbus proved that the earth is round。。4) 现在时刻的状态、能力、性格、个性。 I don't want so much。 Ann Wang writes good English but does not speak well。比较：Now I put the sugar in the cup。 I am doing my homework now。 第一句用一般现在时,用于操作演示或指导说明的示范性动作,表示言行的瞬间动作。再如：Now watch me, I switch on the current and stand back。 第二句中的now是进行时的标志,表示正在进行的动作的客观状况,所以后句用一般现在时。////////////一般现在时表将来 1）下列动词：come, go, arrive, leave, start, begin, return的一般现在时表将来。这主要用来表示在时间上已确定或安排好的事情。 The train leaves at six tomorrow morning。 When does the bus star? It stars in ten minutes。2）倒装句,表示动作正在进行,如： Here comes the bus。 = The bus is coming。 There goes the bell。 = The bell is ringing。3）在时间或条件句中。 When Bill comes (不是will come), ask him to wait for me。 I'll write to you as soon as I arrive there。4）在动词hope, take care that, make sure that等后。 I hope they have a nice time next week。 Make sure that the windows are closed before you leave the room。