[header] How to convince your parents to let you see a movie [title] Search the movie online and check its rating. [step] Go to film review websites such as imdb or rotten tomatoes, and check the movie's rating and the awards it received. Having reliable outside sources that show how good the movie is will help your argument on why you should definitely see this movie. 
[substeps] Ratings are important, but so is their date. A pg-rating in the 70's or 80's is different from a pg-rating today.