Question

Which sentence below shows correct use of an em dash? I have read that book – the first in the series – at least five times. I have read – that book – the first in its series at least five times. I have read that book the first in its series at least five-times. I have read that book the first – in its series at least five times.

Answer 1

The correct answer is the first one, because that is the only option where the em dash is correctly used. I have read that book - the first in the series - at least five times.

Answer 2

The correct answer is A. I have read that book – the first in the series – at least five times.

Explanation:

Em dash (–) is a punctuation mark whose main function is to replace other punctuation marks such as commas (,), parentheses () or colons (;). In the case of replacing parentheses or commas, the em dash is used to add extra information or create a strong break to introduce information that is connected to the main sentence but only clarifies the information. For doing this the Em dash should be placed before and after the extra information, in the case of  "I have read that book – the first in the series – at least five times" the main sentence is "I have read that book at least five times" and "the first in the series" is just extra information that clarifies which book is this person referring to, considering this, it is grammatically correct to use the em dash to add this information and place and em dash before and after the extra information.