We have to find the right linking verb.

1.) It was she/her who was the director. She

2.) The owner of the recording equipment was me/I. I

3.) The engineer helping with the recording was her/she. She

4.) The person testing how the microphone sounded was I/me. I

5.) The conductor was him/he. He

6.) The performers were she/her and us/we. She and we.

7.) The people waiting to begin were they/them. They

8.) It was he/him who sneezed. He

9.) The person who glared was her/she. She

10.) The angriest people in the sound studio were they/them. They

11.) The person worried about wasting time was he/him. He

12.) The ones in the dispute were us/we. We

13.) The unhappiest people were them/they and he/him. They and him.

14.) The peacemaker was me/I. I

15.) The ones who finally got to sing were we/us. We

13, They and HE.

The rest are grammatically correct.

However, our usage of using subject pronouns after linking verbs is changing.

Thanks!

To find the right linking verb in these sentences, we need to determine the correct pronoun to use after the verb "to be" (e.g., is, am, are, was, were). Here's how you can solve each sentence:

1.) It was she/her who was the director.
To determine the correct pronoun, rephrase the sentence without using "who." In this case, you can say: "It was she who was the director." Since "she" is the correct pronoun here, the sentence should be: "It was she who was the director."

2.) The owner of the recording equipment was me/I.
Similarly, rephrase the sentence without using "of" and determine the correct pronoun. In this case, you can say: "The owner was I." Since "I" is the correct pronoun here, the sentence should be: "The owner of the recording equipment was I."

3.) The engineer helping with the recording was her/she.
Again, rephrase the sentence to determine the correct pronoun. For example, you can say: "The engineer was she." Since "she" is the correct pronoun here, the sentence should be: "The engineer helping with the recording was she."

4.) The person testing how the microphone sounded was I/me.
Rephrase the sentence without the dependent phrase to find the correct pronoun. In this case, you can say: "The person was I." Since "I" is the correct pronoun here, the sentence should be: "The person testing how the microphone sounded was I."

Continue this process for the rest of the sentences, rephrasing and determining the correct pronoun.

Note: It's important to consider the context and formality of the sentence. Sometimes, the objective pronoun (e.g., me, her, him, us, them) is more appropriate in informal speech, while the subjective pronoun (e.g., I, she, he, we, they) is more appropriate in formal speech.