drunk drivers

Hi,
Please correct the sentence.

1. Drunk drivers are a cause of 40% of road fatalities.
2. Drunk drivers are the cause of 40% of road fatalities.

3. Drunk drivers is a cause of 40% of road fatalities.
4. Drunk drivers is the cause of 40% of road fatalities.

I know, avoiding the subject-predicate clash would be better, but I do need it for academic purposes.

Thank you.

Number 2 is correct.

1 and 3 would imply that drunk driving is a cause, but not the only cause of 40% of road fatalities. Hence 2 and 4 are correct.

Thanks, guys.

Well I've heard of "bus drivers" and "car drivers", but "drunk drivers"? They drive drunks?

No, only #2 is correct.

The verb always agrees with the subject. Therefore #3 and #4 are ungrammatical. #1 is grammatical but sounds awkward, and, as SpaceFlight pointed out, literally means something like, "Drunk drivers are one of the causes of 40% of road fatalities." Due to the sentence structure, though, it'd probably be interpreted the same as #2, which is fine both grammatically and semantically.

Just in case you're curious about "avoiding the subject-predicate clash", you could take sentence #4 and change "drivers" to "driving", referring to the act rather than the people who do it.

- Kef

A very nice explanation, Kef, but claiming <The verb always agrees with the subject> is somewhat simplistic. It's a treacherous turf.