The sentences Mom said, "When you’re finished with the dishes, I have more work for you", "Marcus got down on one knee and proposed right then and there," she squealed, The intercom squawked, "Send her in. Now!" are properly format dialogue.
Explanation :
Dialogue sentences comprise of two parts: the dialogue and the dialogue tag. In sentence 2, Dialogue tag: mom said
Dialogue: “When you’re...for you.”
The dialogue showcases the speech or the spoken words and the dialogue tag identifies the speaker. In order to show the ‘uttered sentence’, format of direct speech is used.
The words of the speaker are put in double inverted commas or quotation marks. They end with a comma before the last quote mark followed by the dialogue tag. When not using dialogue tags in the end, put period before the last quotation mark. They said, “Put your money in your wallet.”
In case of interrogation and exclamation, put the mark of interrogation and exclamation inside the last quotation mark. “You are quite rich, aren’t you?” The dialogue tag can come before and after the dialogue.
In second sentence, the dialogue tag comes in front followed by a comma, the opening quotation mark, the dialogue, the period and the closing quotation mark. Quite appropriate.
In fourth sentence, the dialogue tag, comma, opening quotation mark, dialogue, exclamation mark, closing quotation mark. Quite according to the format.
In the third sentence, as the dialogue tag appears in the end, the dialogue ends with a comma as no exclamation mark is there.