grammar conundrum of the day

[chhotii]

Consider these sentences:
John is driving to Sacramento.
The twins are driving to Sacramento.
Either John or Ben is driving to Sacramento.
So far so good, yes? But what about:
Either John or the twins are driving to Sacramento. (?)
Does that seem correct to you?

Comments

[ceo]

That sounds right to me, and my brain flags syntactical errors pretty hard.

[whitebird.livejournal.com]

All of those sentences sound proper to me.

[achinhibitor.livejournal.com]

It is correct -- if two noun phrases are connected with "or", then the disjunction is grammatically singular if both of the components are singular, and grammatically plural if either or both of the components are plural. (A conjunction (formed with "and") is always grammatically plural.)

I'm sure the rule is more or less arbitrary, but that's what I was taught in eighth grade.