Question

is this /a book /you /want to buy (spot the error)​

Answer 1

Explanation:

is this a book you want to buy

Here a is the error and the should be in place of a

Answer 2

Answer:

Is this the book you want to buy?

Explanation:

The error was using “a” instead of “the”.

“A” is an indefinite form meaning is used in the case when referring to any object in particular. For example, she owns a cat. There are many cats in the world and it could be that the message is conveyed to the person who doesn’t even know the cat owned.

Therefore, the cat, in this case, is random and not specific. Using “the” on the other hand means the object of discussion is specific as in the case of the book. It is evident by using “this” indicating that the book referred to is singled out either by pointing at it, holding it or etc.