otherwise,but for ,without 虚拟语气里用法及结构：
1、without, otherwise, but for 引导的短语或句子有时相当于一个虚拟条件句。假设的情况并不以条件从句表示出来，而是暗含在上下文中，通过介词短语来表示。
2、使用到这些词组的句子中，虚拟语气的用法一般是：对现在的虚拟：would+do；对过去的虚拟：would(not) + have done。
拓展资料
otherwise
1、Make a note of the questions you want to ask. You will invariably forget some of them otherwise
把想提的问题记下来，否则总是会漏掉其中的一些。
2、The decorations for the games have lent a splash of colour to an otherwise drab city.
为运动会所作的装扮给原本毫无生气的城市增添了一抹亮色。
3、Take approximately 60mg up to four times a day, unless advised otherwise by a doctor
每次服用大约60毫克，每天最多4次，或遵医嘱。
4、The studio could punish its players by keeping them out of work, and otherwise controlling their lives.
电影公司能通过让艺人坐冷板凳来惩罚他们，并采用其他方式控制他们的生活。
5、It was for the police to assess the validity or otherwise of the evidence
应该由警方来判定证据有效与否。
but for
1、I'd have been lost but for you.
要不是你，我就走迷路了。
2、But for you, they might have given us the slip.
要不是你，我们可能已经被他们甩掉了。
3、But for me television is an escape.
但是对我而言，看电视是一种逃避的方法。
4、But for your help, I might have failed.
假如没有你帮忙，我兴许会失败。
5、You may consider it useless, but for our customers it's an all-important sign of good service.
您也许会认为这样毫无用处，可是对于我们的客户而言，它却是优质服务的重要体现。
without
1、I don't like myself without a beard
我不喜欢自己没胡子的样子。
2、He was offered a generous pension provided he left without a fuss
他如果一声不吭地离开，就会获得一笔丰厚的养老金。
3、Janet Magnusson watched his approach without enthusiasm
珍妮特·马格努森冷冷地看着他走过来。
4、They worked without a break until about eight in the evening
他们一刻不停地干到晚上8点钟左右。
5、Alex had done this without consulting her.
亚历克斯这么做事先并没有跟她商量。