I've looked this question up and found out that the words and phrases to be categorized are the ones highlighted below:
"Carl, what did you think of the film?" Russell asked eagerly.
Carl hesitated to respond. He thought it was confusing and poorly made, but he didn't want to hurt his friend's feelings. After all, Russell worked so hard to produce it.
"Well, I will say it was interesting, with lots of twists in the plot."
Answer:
Inner monologue → 'confusing' and 'worked so hard'
Actual dialogue → 'what did you think' and 'twists in the plot'
Explanation:
In the excerpt above, the actual dialogue is clearly marked by the use of quotations. The sentences that are inside the quotation marks are the ones being said out loud by the characters, Carl and Russel. Therefore, whatever is found inside the quotations should be categorized as actual dialogue:
Actual dialogue → 'what did you think' and 'twists in the plot'
On the other hand, there is a part of the excerpt that tells us about Carl's thoughts and opinions. This part is not enveloped by quotation marks, which shows it was not said out loud. Carl is only reflecting to himself. Thus, whatever is found in this part should be categorized as inner monologue:
Inner monologue → 'confusing' and 'worked so hard'