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Watching a reproduction of a classic in a different format, such as a play turned to a movie, enhances the understanding of the original work by giving the audience a different perspective of what the author originally intended to show. Also, it may solidify the original intention of the author, since movies are technologically rich and more dynamic than plays. Hence, that which is funny and new in a play may result more funny and more new in a movie.
The Importance of Being Earnest was like the "Mega Movie" of its day. It was THE most important and popular play of 1895. Everyone who was somebody went to the St. James's theater on Valentine's day for its premiere. Even those reporters and critics who had a grudge against Wilde since his 1890 publication of The Picture of Dorian Gray had to give credit where credit was due: the witty dialogues, the situational irony, and the peculiar comments of The Importance of Being Earnest deserved the praise that they got from all Victorians.
However, that was 1895. A lot of the humor that Wilde employs in his dialogue is colloquial and typical of that time period. Some of the language is over-used since it is meant to be a comedy of manners set in a fashionable part of the very fancy London West End. Therefore, the modern, American reader may find it very hard to connect the humor that Wilde used with today's use of monikers, sarcasm, and irony.
The film The Importance of Being Earnest had a very impressive cast that included British luminaries Colin Firth and Ruper Everett as Jack and Algy. This was the same effect that, in 1895, George Alexander and Allan Aynesworth caused in his audiences due to their own popularity.
The benefit of having a powerful cast interpret so convoluted characters such as Jack and Algy is that the actors in the movie are able to say more, express more, and have more freedom to use non-verbal cues to help the audience understand the humor. Also, since the actors do not have to follow the strict parameters set by stage directions, they can avoid any potential misrepresentation of the character by adding on more traits that enforce what Wilde originally intended. For instance Everett made Algy even more libertine and used his voice to emphasize the extent to which Algy REALLY did not care about measuring the consequences of his actions.
Moreover, the female actresses gave a wonderful rendition of the typical aristocrat snobby debutantes and their mothers, and the characteristic oblivion of the upper-classes was even more evident in film that they could ever be in theatrical form. Therefore, the freedom of the actors to re-interpret their roles outside of the parameters placed by Wilde's stage directions certainly help the audience to perceive the character from a more, in-depth perspective, hence allowing them to understand the characterization better.