until now , to date , as yet , so far分别用于什么时态

Question

再给几个例句，谢谢。

Answer 1

until now 1.Until now this seemed to be working。
直到现在，这个策略似乎仍在运作。
2.By this reckoning, they have done well until now。
在这一点上，直至今日他们一直做的很好。
to date 1.To date, all patients under investigation have received treatment with this drug. 到目前为止，接受调查的所有病人都使用这种药物进行治疗。
2.The problem at this point was not with the dating method; the problem was finding the right thing to date.。
该问题在这一点上并不符合测定日期的方法，问题是找到要测日期的事物。
as yet 1.There was to be a fourth thing, but as yet he knew nothing of it.
2.How this might pertain to choices that people might make is, as yet, unclear.
这些方式怎样附属于人们可能做出的选择至今仍未明了。
so far 1.So far I have no regrets.
到目前为止，我并不后悔。
2.So far, they appear to be up to the task
到目前为止，他们表现出承担了这一任务。追问

它们分别用于什么时态？

参考资料：有道词典