by now用什么时态

by now是现在完成时的标志，另外还有so far，till/until now,up to now。都使用现在完成时。By now you will have guessed that I'm back in Ireland.你现在应该已经猜出我回到了爱尔兰了。

by now是现在完成时态。

by：adv. 通过； 经过； 表示保留或保存时用； 短暂拜访。

now：adv. 现在； 目前； 此刻； 从现在开始； 表示厌烦。

He'll be home by now.

他现在该到家了。

If he started out at nine, he ought to be here by now.

他如果九点出发，现在应该到这里了。

By now the passengers were getting browned off with the delay.

此时乘客们对延误已开始感到不满。

Oughtn't the water to have boiled by now?

水现在该开了吧？

Any plans I'd had for the weekend were by now well and truly snookered.

我原先设想的各项周末计划，这时候就彻底落空了。

by now和till/until now的区别

1、by now到目前为止；到如今；到现在为止；直到如今，语气平淡，只是单纯的叙述这件事，可用于多种时态。

例如：He would have been there by now if had not missed the train.

如果不是误了火车的话，他现在应该已经到那里了。

2、till/until now：当主句是否定句时，它的意思是"直到（某时）（某动作）才（发生）"这时候常会出现"not until…"的结构，如果将"not until…"的结构放在句首，那么主句要写成倒装句。此两个连词意义相同。

肯定形式表示的意思是"做某事直至某时"，动词必须是延续性的。否定形式表达的意思是"直至某时才做某事"。动词为延续性或非延续性都可以。正确使用这两个连词的关键之一就在于判断句中的动词该用肯定式还是否定式。Until可用于句首，而till通常不用于句首。

例如：Until you told me, I had heard nothing of what happened.

直到你告诉我以前，出了什么事我一点也不知道。

They musthavearrived by now.

现在他们肯定已到了。

by now和so far有什么区别

by now和so far的区别：by now表示的意思为到目前为止，但是后面没有要加消极信息的那一层意思，也没有严格的时间点或地点的要求；so far意为如此程度、迄今为止，表示时间点或地点，后面的句子一般用完成时。

一、by now的含义及用法介绍

by now意为此刻已经、到现在为止，后面没有要加消极信息的那一层意思，也没有严格的时间点或地点的要求。

例句：She'll have had the results by now.

她现在应该知道结果了。

She would be in bed by now, as like as not.

这工夫她很可能睡了。

If you think about it, those children must be at school by now.

想想吧，那些孩子现在一定在学校了。

If he started out at nine, he ought to be here by now.

他如果九点出发，现在应该到这里了。

By now the passengers were getting browned off with the delay.

此时乘客们对延误已开始感到不满。

There should be some snowdrops out by now.

现在应该有雪花莲开放了。

By now all logic had gone out of the window

到这时根本就不讲什么逻辑了。

She's a very sweet woman, as you no doubt know by now.

她是一个非常温柔的女人，你现在肯定知道了。

二、so far的含义及用法介绍

so far意为如此程度、这个地步、迄今为止、到目前为止，后面一般接比较贬义或者消极的信息，且句子用一般完成时时态。

例句：How many driving lessons have you had so far?

你到目前为止上过多少节驾驶课了？

So far, the police investigation has drawn a blank.

到目前为止警方的调查毫无结果。

What do you think of the show so far?

到目前为止你觉得这场演出怎么样？

They have not had a win so far this season.

他们这一赛季迄今还没有赢过一场。

I've saved almost ￡ 100 so far.

我至今已经攒了差不多100英镑了。

All talks have so far been conducted through an intermediary.

到目前为止所有的谈判都是通过调停人进行的。