The first sentence of this news report is perfectly fine, but it presents a linguistic puzzle:
The leader of the International Monetary Fund and a possible candidate for president of France was arrested Sunday in connection with the violent sexual assault of a hotel maid after being yanked from an airplane moments before it was to depart for Paris, police said.
The puzzle is how such a conjunction can denote a single person, as it clearly does in this sentence. It could even more easily denote two, but then we’d see “were arrested”, not “was arrested”.
First a descriptive query: do all languages allow such a conjunction of a definite and an indefinite singular noun phrase in subject position, interpreted as referring to a single person? And does English allow it quite generally, or is this a special newspaper style?
If the conjunction occurred in the predicate, “Dominique Strauss-Kahn, 62, is the leader of the IMF and a possible candidate …”, I would know how to analyze it – I’ve written about interpreting indefinite and definite noun phrases in different ways, with different “semantic types”, including a “predicate type” for such predicate positions. Then the “and” gets a straightforward interpretation as a conjunction of properties – So-and-so is both the leader of the IMF and a candidate for president, fine.
But the subject of a sentence isn’t normally interpreted predicatively. I know how to explain a subject noun phrase containing two descriptions of a single person when it has a conjunction of common nouns under a single article, as in “The president and commander-in-chief”, or “A prominent poet and essayist”, since the common nouns themselves have “predicate type”, and the interpretation of “the” or “a” then gives the whole noun phrase its referential or specific interpretation as a single individual.
But in the sentence above, if we start from the usual referential or specific interpretation of each of the two conjoined noun phrases, everything I know about the interpretation of “and” would lead me to conclude that the conjunction would have to come out plural. (In fact that’s so even if they have the same denotation: Superman and Clark Kent are (not is) the same person. Though come to think of it, you can't very well put two co-referential proper names in an example like the sentence we started from, neither with singular nor with plural — it sounds anomalous to say "Superman and Clark Kent was/were arrested ..", doesn't it?)
This is mainly a puzzle for analysis; maybe I should be searching the linguistic literature and if I don’t find a solution there I should start working on one. Intuitively, it seems to call for something similar to an analysis Emmon Bach long ago suggested for all noun phrases (not something he held onto), where there is some ‘covert’ head noun with those two noun phrases connected to it in a predicative manner, e.g. “a person who is the head of the IMF and a candidate for president.” That would get the right semantics just fine. (And it would probably even explain why it's hard to do the same thing with two proper names, since proper names don't so easily get predicative meanings.) But I don’t like to posit otherwise unmotivated invisible “deep structure” (or extra invisible stuff at some level of “logical form”) just to get the semantics to come out right – that feels like cheating.