Question 3

Janet called her dog, who had run after a squirrel.

The phrase that makes the sentence grammatically correct is "dog, who had," as it appropriately introduces a non-restrictive relative clause providing additional information about the dog.

A) dog, who had

This option is correct because it uses a comma to introduce a non-restrictive clause, which adds information about the dog without limiting the subject. The phrase "who had" is correctly used here to describe the dog's action.

B) dog that had

This option is incorrect because "that" is typically used for restrictive clauses, which are essential to the meaning of the sentence. In this context, the additional information about the dog is non-restrictive, making "that" inappropriate.

C) dog, that had

This option is incorrect because the use of the comma before "that" is not standard in English grammar. "That" introduces a restrictive clause, and placing a comma before it suggests a non-restrictive clause, which creates confusion.

D) dog who had

While this option might seem correct, it lacks the necessary comma that indicates a non-restrictive clause. Thus, it does not clearly separate the additional information about the dog from the main clause of the sentence.

Conclusion

Option A is definitively correct because it properly employs a comma to introduce a non-restrictive clause, enhancing clarity and grammaticality. The other options either misuse relative pronouns or punctuation, failing to convey the intended meaning effectively. Therefore, understanding the distinction between restrictive and non-restrictive clauses is crucial for selecting the correct phrasing.