It's very difficult to concentrate ___ prepositions!

It's very difficult to concentrate ___ prepositions!

• A. On
• B. In
• C. With
• D. At

Answer: (A)

The verb concentrate is commonly followed by the preposition on to show what your attention is directed toward. Here, the thing you’re focusing your mental effort on is “prepositions,” so the natural collocation is concentrate on prepositions. That’s why the sentence reads: It’s very difficult to concentrate on prepositions. Using other prepositions doesn’t fit the usual pattern. In would suggest being inside or within something, which doesn’t convey directing attention. With would imply using something or being accompanied by something, which isn’t how concentrate is used to mean focusing. At isn’t used to indicate the target of attention in this context either.

The verb concentrate is commonly followed by the preposition on to show what your attention is directed toward. Here, the thing you’re focusing your mental effort on is “prepositions,” so the natural collocation is concentrate on prepositions. That’s why the sentence reads: It’s very difficult to concentrate on prepositions.

Using other prepositions doesn’t fit the usual pattern. In would suggest being inside or within something, which doesn’t convey directing attention. With would imply using something or being accompanied by something, which isn’t how concentrate is used to mean focusing. At isn’t used to indicate the target of attention in this context either.