"The last two nights in Las Vegas have been wonderful."
Is this sentence grammatically correct? I think it's better to use past simple as the last two nights are finished now.
"The last two nights in Las Vegas have been wonderful."
Is this sentence grammatically correct? I think it's better to use past simple as the last two nights are finished now.
If the speaker of the sentence is no longer in Las Vegas, then he would use the past simple. This is because the events the last two nights in Las Vegas are indeed completely in the past. They do not extend to and include the moment of speaking.
If the speaker is still in Las Vegas and uses the present perfect, which is the most natural scenario, it means he is including the moment of speaking in the time period of the last two nights. In other words, the last two nights are still in progress if the present perfect is used.
If the speaker considers the last two nights to be over and not part of the moment of speaking, he would use the past simple. This could be done to stress that the last two nights are completely over and done with. Example: it's the third day, and Jill wants to break up with Jack; she could say The last two nights in Las Vegas were wonderful, but I'm still breaking up with you (here on this third day in Las Vegas). This example is a little forced but it just shows that the expression the last two nights is usually going to take the present perfect if a location is given and the speaker is still at that location.
You can think of "the last two nights" as two separate spans of time that began at about 8:00 p.m. on each night and ended when you went to sleep each night, or you can think of "the last two nights" as part of a series of nights that started two nights ago and continues up to the present.
The choice between simple past and present perfect leads your listener to think of the last two nights the first way or the second way, respectively. The present perfect usually leads the listener to understand the past events as part of a process of interest that is still continuing (or just started or just finished). That process is not necessarily mentioned in the sentence, as the examples below will illustrate.
Suppose that Valerie thinks of Las Vegas as a den of sleaze and organized crime, and didn't want to spend her vacation there, but she reluctantly agreed to go on a four-day trip to Las Vegas with her friend Joanne. On the morning of the fourth day, they have this conversation:
Joanne: So, have you enjoyed the City so far?
Valerie: I must admit, the last two nights in Las Vegas have been wonderful. But there are still two more days to go.
Valerie uses the present perfect here to suggest that she wants Joanne to understand the last two nights as a time interval that continues to the present and as part of something continuing beyond the present: the vacation. Notice that nobody ever said "vacation". In the situation, the present perfect is enough to suggest it.
Now suppose that Joanne and Valerie are talking about the vacation 20 years later—long after the two nights and long after the end of the vacation:
Joanne: So, how did you enjoy our summer vacation in 1997?
Valerie: The first two nights in Las Vegas were wonderful. The last two nights, though, were a disaster. I lost every cent I had in a long run of bad luck at the blackjack tables.
Valerie uses the simple past because the story in which those nights are events is over. The vacation is over, and you're talking about the events in connection with the vacation, so the events that are part of the vacation go in the simple past tense.
By the way, people wouldn't ordinarily say "The last two nights in Las Vegas have been wonderful" except to distinguish them from nights at other locations. This conversation is a little more plausible:
Vito the Boss of Many Casinos: So, how's the take this week?
Joe the Manager of the Casinos in Tahoe and Las Vegas: Tahoe has been in a dry spell: we barely broke even all week. But the last two nights in Las Vegas have been wonderful: we made $400,000 both nights.
By using the present perfect, Joe suggests that he thinks the high revenue might continue. If he had used the simple past, then he would have reported the same facts without suggesting anything about whether the high revenue will continue.
Also, this conversation, on the fourth morning, is more plausible:
Joanne: So, have you enjoyed Las Vegas so far?
Valerie: Well, the first night was a disaster, but the last two nights have been wonderful.
The first night is over, and it doesn't extend to the present, so Valerie talks about it in the simple past. She distinguishes it from the present situation, which she frames as part of a span of time that began two days ago. Valerie doesn't mention Las Vegas because there's no distinction to make about the last two nights regarding location.