I came across one sentence in the book: “$200 buys you 181 Swiss Francs”. Could you please explain why the verb takes -s if the noun is plural. And what is the meaning of the sentence?
1 Answer
Because "two hundred dollars" is being treated as a single thing: you can think of it as "the sum of $200" if you like.
We often do this with sums of money: often they can be singular or plural, with little difference in meaning. The iWeb corpus has 11591 instances of "dollars are", against 5230 of "dollars is". Many of the cases of "dollars is" are not like your example, but have a phrase ending in "dollars" followed by "is"; but the first hit is "20 dollars isn't a lot of money".
The sentence is saying that if you were to exchange your $200 with a money changer, the number of SFR you would get ("buy") with it would be 181.