*Half the sheep are dead* (half of the number of multiple sheep). Somewhat less likely, *Half the sheep is dead* (one sheep, half of whose body is necrotised?).
– FumbleFingersJan 18 '23 at 17:05
@FumbleFingers - But (countable) sheep are different, surely? Is it "(a portion of the crop equal to 2/3) is" or "Two (portions equal to 1/3) are"? I think I'd go for the latter.
– Kate BuntingJan 18 '23 at 17:10
1
Arguably this should have beenn migrated to English Language Learners. But see this NGram showing that it's virtually always *Half the crop is destroyed, not ...are destroyed. Don't be distracted by the fact that it's two thirds* - it's still *A fraction*.
– FumbleFingersJan 18 '23 at 17:13
@KateBunting: Plural makes more sense with, say, Two-thirds of the herd* are infected. But for nearly all possible referents, there's at least the possibility* of using the "less-favoured plurailty". My tongue-in-cheek sheep example was supposed to show that there are at least some contexts where one plurailty would be extremely unusual! :)
– FumbleFingersJan 18 '23 at 17:17
As I understand it, Brits happily switch between *couple is* and *couple are* depending on whether we're thinking of the couple "collectively" or as two people, and we do the same with a *herd* (not so much with a *crop, though). But maybe Americans are more wedded to two-thirds is*, same as with couples.
– FumbleFingersJan 18 '23 at 17:23