只是时间不同， present perfect 是过去发生的事一直持续到现在或有可能继续下去，过去发生的事对现在造成的影响。past perfect是过去的过去发生的事一直持续到过去的某个时或有可能继续下去，
past是个介词和副词，而pass是个 这两个词好比across 与cross 一个能单独使用 一个不行 perfect 做名词用就是完美 的意思 做形容词就是完美的 理想的 的意思 present做形容词是出席的 到场的 做名词用就是目前啊 现在啊（一般at present=at the moment =now) 做动词用就是显示 出现...
past perfect,present perfect,simple past,past perfect,past passive,simple past,simple past,past passive (1)past perfect。考查过去完成时。题干中谓语是"had begun",begun是begin的过去分词,可判断时态为过去完成时,谓语结构为"had+过去分词"。故答案为:past perfect。(2)present perfect。考查现在完成时。根...
For example, “I have had a cold”. So is this the present perfect because of ‘have’, or is the past perfect because of ‘had’? In order to identify the correct tense, always look at the first ‘have’ or ‘had.” In this sentence, we first used ‘have’, therefore this ...
1. I haven't seen the new Hobbit film yet. 2. Have you ever been to London? 3. John took his exam last week. 4. Nina got here a few minutes ago. 5. They haven't eaten at this restaurant before. 6. I haven't eaten breakfast so I'm really hungry and it's two hours till ...
前面是现在完成进行时表示从过去的动作一直持续到现在也可以延续到将来，这里没有错；后面用过去完成时表示动作已经完成了。
past perfect The past perfect is about an event in the past which usually has nothing to do with the present. The present perfect is about an event in the past which still has an effect in the present.的同义词
Me too! And I fight the urge to slap them.
Past perfectBoth tenses are used to place events into chronological order. We use the present perfect tense, when an action began in the past, and it ends now in the present. I have lived in Texas for six years. Now, my job requires me to move to Arkansa
完成进行perfect continuous现在完成进行时present perfect continuous过去完成进行时past perfect continuous将来...