Relative Pronoun ?

The difference between these is that in the first, the adjective clause is a restrictive one, meaning it is necessary to identify which book we are talking about. There are several books, and we only mean the one that Peter wrote. If we omitted the clause, someone would want to know, "Which book?"

In the second, the adjective clause is nonrestrictive, meaning it just provides extra information. The book has already been identified, or maybe there is only one book under discussion, so we don't need the information in the clause to understand the thought. Commas always set off a nonrestrictive adjective (or relative) clause.

The antecedent in both clauses is "book."

Que skill "that" it solutions WHAT Quien skill "Who" relies upon on the sentence, merely ask your self which way will the sentence sound better, while utilising what or who. If that's a guy or woman you're speaking approximately then you definitely might desire to apply QUIEN, yet while that's a place or merchandise you employ QUE ex: Quien es el padre del nino? ex: Que hora es?

In sentence 1 "which Peter wrote" qualifies the antecedent "book", for there are no commas and so the clause qualifies the noun immediately before it.
In sentence 2, the use of commas suggests that Peter wrote the account number, which is therefore the antecedent.