Question

is "I am so excited to see the movie that opens tomorrow!" that uses the pronous "that" an essential clause?

Answer 1

Yes, the clause "that opens tomorrow" in the sentence "I am so excited to see the movie that opens tomorrow!" is an essential (or restrictive) clause. It provides necessary information to specify which movie you are referring to—without it, the sentence would be less clear about which movie you're excited to see. Essential clauses typically use "that" and are not set off by commas, as they are crucial for the meaning of the sentence.