Which comma rule is used in the sentence? We are excited for summer vacation, for we have plans to plans to visit several national parks.

The comma rule used in the sentence is the rule for separating two independent clauses with a coordinating conjunction.

The comma rule used in the sentence is the use of a comma before the coordinating conjunction "for" in a compound sentence.

The comma rule used in the given sentence is the comma used to separate two independent clauses joined by a coordinating conjunction (in this case, "for"). This rule is commonly known as the comma before a coordinating conjunction.

To identify and apply this comma rule, follow these steps:

1. Read the sentence and locate any coordinating conjunctions (and, but, or, nor, for, so, yet) that connect two independent clauses.

2. Determine if each side of the conjunction can stand alone as a complete sentence. In the given sentence, "We are excited for summer vacation" and "we have plans to visit several national parks" are both complete sentences on their own.

3. Place a comma before the coordinating conjunction (in this case, "for") that joins the two independent clauses. So, in the given sentence, a comma is used before "for."

Therefore, the comma rule used in the sentence is the comma before a coordinating conjunction.