1、当句中出现的表示时间的词是now,at the moment(此刻、现在)等时,表示句子要说明的是现在正在发生的事,动词应用现在进行时。
Linda's brother is watching TV in his bedroom now.
现在,琳达的哥哥正在他的卧室里看电视。
2、当句中出现的时间状语是these days,this week,this month,this term 等时,如果句子所要表达的意义是在这一阶段正在发生的事,则动词应用现在进行时。
These days we are helping the farmers work on the farm.
这些天我们在农场帮农民们干活。
They're having a test this week.
这一周,他们在进行一次考试。
3、在句中出现了Look,Listen,Can't you see? 等暗示词时,说明后面谓语动词的动作正在发生,该动词应用现在进行时。
Look! Maria and Tom are dancing under the tree.
看!玛丽亚和汤姆正在树下跳舞。
Listen! Our English teacher is singing the popular English song.
听!我们英语老师正在唱那首流行的英文歌曲。
Many children are swimming in the river. Can't you see?
许多小孩在河里游泳,你难道看不见吗?