The plot involves a guy named Jack who leads a double life. In London, he is known as Ernest Worthing, while in the country he is John 'Jack' Worthing who has a brother named Ernest. His friend, Algernon, also leads a double life, which Jack calls “Bunburying,” because he makes up an invalid person named Bunbury to get away from things. Jack is in love with Algy's cousin, Gwendolen, and she is too, in love with him – or to put it more plainly, his name. Algy, curious to know his friend's life in the country, goes there as Ernest – Jack's brother. There he meets Cecily, a young girl under Jack's guardianship. He likes her, and she likes him as well – as Ernest. To make things more complicated, Gwen goes there as well to meet his fiance, Ernest. The rest is for you to read.
The play is witty and funny, but if you're looking for serious stuff or moral lesson, the book is not to be recommended. It mostly contains Wilde's smart sarcastic remarks on life and society. The plot itself is not so different from normal Shakespearean comedy, and therefore, enjoyable. Better still, it contains nothing inappropriate. It's perfectly funny, and not at all serious.
Having praised it so much, I still don't understand why I don't give it a good score on Goodreads. I only give 3 stars for it. Maybe it's because the language is so so simple and straightforward, not at all romantic or beautiful. Even though I don't really like it, it's still a worthy book to read.