[Grammar] Nothing On Earth Could Come Between Them

[kadioguy]

(On a Titanic poster)

Nothing On Earth Could Come Between Them.

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Questions:

1.
I am not sure why the "could", rather than "can", is used. I have thought of three possible answers:

a. This (true) event happened in the past.

b. "Could" here is used for saying that something is possible or that it may happen.

c. Both (a) and (b) are possible.

2.
However, I think that it is possible to use "can" in the original sentence, for dramatic emphasis.

What do you think?

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(Source)

 

[PeterCW]

Native speakers regularly confuse "could" and "can".

In spoken English "could" sounds more emphatic with the hard "d" sound at the end and, as such, works better as part of the strapline.

 

[Charlie Bernstein]

And using the past-tense could gives it an epic quality: Nothing could. Nothing did.

 

[tedmc]

The epic event happened more than a hundred years ago after all.

 

[jutfrank]

1) I read could with a real past time meaning. In other words, It was not possible for anything to come between them. I think this reading fits the fact that this is a historical film—the effect of could is to place the narrative firmly in real past time.

2) Yes, I agree.