"until now" + the present perfect

[YAMATO2201]

Until now, little has been known about the Roswell UFO crash.

Is this sentence correct and natural?

I have no idea whether or not I should remove "Until now".

 

[teechar]

Remove it. You could use "so far" instead.
Edit: it's not incorrect or unnatural, but I prefer "so far" to it.

 

[YAMATO2201]

Remove it. You could use "so far" instead.
Edit: it's not incorrect or unnatural, but I prefer "so far" to it.

1) "So far, little has been known about the UFO crash. The investigation team should try a different approach."

2) "Until now, little has been known about the UFO crash. But the situation has changed. This morning, Scott discovered two amazing facts about it."

"Are these correct and natural?

 

[teechar]

1) "So far, little has been known about the UFO crash. The investigation team should try a different approach."

That sentence is okay but somewhat unusual. However, I suppose the UFO could have crashed on some other planet!

2) "Until now, little has been known about the UFO crash. But [STRIKE]the situation has[/STRIKE] that all changed this morning, when Scott discovered two amazing facts about it."

 

[YAMATO2201]

I don't think that "so far" and "until now" are necessarily interchangeable. Am I correct?

 

[teechar]

You're right. There's certainly much overlap between them, but they're not interchangeable.
For example,
The investigation is ongoing but this is what we know so far. :tick:
The investigation is ongoing but this is what we know until now.

Here are six facts about the Roman Empire you probably didn't know about until now.

Here are six facts about the Roman Empire you probably didn't know about so far.

 

[emsr2d2]

"Until now" certainly suggests to me that something has changed about that situation. I would also associate it with a change of verb.

Little is known about the crash. (The situation remains unchanged.)
Little was known about the crash until now. (We probably now know something new.)

 

[YAMATO2201]

Until recently, little had been known about the UFO crash.

Is this sentence correct and natural?

 

[teechar]

Yes and yes.