1. The book opens with a lengthy description of the era: The French Revolution. An English woman named Lucie Manette goes to Paris in search of her father who she had thought was dead until recently. She finds her father who is now not his normal self for being imprisoned for a long time. Back in England, a man named Darnay is accused of a crime, and is acquitted because of a drunk lawyer named Carton. They both end up having feelings for Lucie, and Darnay even marries her, but both get executed because of the craze of the French Revolution.
2. I would say that the main theme is that sometimes, circumstance will lead to tragedy regardless of what you do.
3. The author uses an emotional and poetic tone to better connect with the reader's emotions.
"Waste forces within him, and a desert all around, this man stood still on his way across a silent terrace, and saw for a moment, lying in the wilderness before him, a mirage of honorable ambition, self-denial, and perseverance."
"The barrister was keen enough to divine that the banker would not have gone so far in his expression of opinion on any less solid ground than the moral certainty. Unprepared as he was for the large pill he had to swallow, he got it down."
"He bent over the golden head, and put the rosy lips to his, and folded her in his arms. If one forlorn wanderer then pacing the dark streets, could have heard her indecent disclosure, and could have seen the drops of pity kissed away by her husband from the soft blue eyes so loving of that husband, he might have cried to the night-and the words would not have parted from his lips for the first time."
4. The author uses a lot of comparison and parallelism especially in the opening. "It was the best of times, it was the worst of times" I really should complete that quote, but I'm tired, and you should be able to find it online quickly. The author uses setting to put the characters in a place where their world is falling apart around them in a very unique way. I don't think this story would be that similar in another setting. The author uses metaphor such as in the quotes above, with the "large pill" and "drops" of pity being "kissed away." The author also uses characterization so you can develop a connection with the characters so their downfall is that much more meaningful.