The girl who I was talking about… (defining relative clause)

A defining relative clause, also known as a restrictive relative clause, is a type of clause that provides essential information about a noun. It defines or restricts the meaning of the noun it modifies. These clauses cannot be omitted without changing the essential meaning of the sentence. Defining relative clauses is usually introduced by relative pronouns such as "who," "whom," "whose," "which," and "that." These clauses give crucial information, specifying which person or thing we are talking about.

Structure:

1. Relative Pronoun: This is the word that connects the relative clause to the main clause and begins the clause. The choice of relative pronoun depends on the noun being modified (e.g., "who" for people, "which" for things, "whose" to indicate possession, etc.).

2. Subject and Verb: The relative clause contains a subject and a verb that provide additional information about the noun in question.

Examples:

1. The woman who lives next door is a doctor.

   - In this sentence, the relative clause "who lives next door" defines which woman we are talking about. It's not just any woman; it's the one who lives next door.

2. The book that I borrowed from the library was very informative.

   - Here, the relative clause "that I borrowed from the library" specifies which book is being referred to. It's the book that the speaker borrowed from the library.

3. The car whose color is red belongs to John.

   - In this case, the relative clause "whose color is red" tells us which car we're discussing. It's the one with the specific attribute of having a red color.

Rules and Notes:

1. Omission of the Pronoun "That": In defining relative clauses, the relative pronoun "that" can often be omitted, especially in informal speech. However, it's usually retained in formal writing.

   Example: The dress (that) she wore to the party was stunning.

2. No Commas: Defining relative clauses are not separated by commas from the rest of the sentence. Commas should not be used before or after the relative clause.

   Example: The restaurant that serves Italian cuisine is my favorite.

3. "Whom" vs. "Who": While "whom" is the formal object pronoun, it is becoming less common in modern English. It's acceptable to use "who" for both subject and object in defining relative clauses.

   Example: The person who(m) I invited to the event couldn't make it.

4. "Which" vs. "That" for Things: "Which" is often used for non-restrictive relative clauses (ones that provide additional information but are not essential to the sentence). In defining relative clauses, especially with restrictive meaning, "that" is preferred for things.

   Example: The laptop that needs repair is on the table.

In summary, defining relative clauses are used to specify a particular noun by giving essential information about it. They are introduced by relative pronouns and cannot be removed without affecting the core meaning of the sentence. It's important to distinguish between defining and non-restrictive (non-defining) relative clauses, as the latter are set off by commas and provide additional, non-essential information.