Girl on the Train In Class Trailer Analysis

The trailer begins with a characters dialogue and is an introduction to her life. She speaks very seductive and in a few of the clips showing her character there is usually something sexual happening someone. Also the clothing that she wears links to her character being sexy and desired. There is many intertitles throughout the trailer which shows the production companies etc and also link to the storyline, like 'at 4:36 pm' telling you the time the woman went missing. The scene of the woods with police tape tell the audience it was a crime scene where the woman was killed. The female with the brown hair, who seems to be the main character is then shown saying she saw the woman being taken by a man and she saw this whilst being on the train. This links to the title of the film 'the girl on the train' and suggests that there is bigger important behind the train and her character is hiding something about the moment she sighted her.
Through the trailer her story develops and you see her trying to find evidence, possible to help solve the crime, however later in the trailer she says there is time missing in her day that she cant recall making the audience believe she has something to do with the death of this woman, so could have been looking for evidence her help what she did not be discovered. The trailer shows twists in the story which make the audience confused and wanting to know more. This makes the trailer effective as its purpose is to get people to see the film. 
The music used goes well with the clips. At the start the music is slow and as soon as things start going wrong the tempo begins to increase. During the montage of clips toward the end of the trailer, there is a part of the song where it is louder than the rest and when this happens it jump cuts to the next scene showing action, like the mirror being smashed. 
There is dialogue when the woman mentioned her husband to where the detective corrects her saying ex-husband and turns out the woman who was killed was his nanny. This suggests that the woman who was killed was seductive toward her ex-husband and they probably had sex, making the audience assume she is jealous of the woman or angry as she slept with her ex-husband as by still calling him her husband shows she's still in love with him so this led her to kill her.
The clips are edited well together with background to the character who was killed at the beginning which is like the 'calm before the storm' as after the clips begin to have more action in them and more upbeat music begins which makes the audience heart rate and interest increase.  
One of the intertitles said 'based on the thriller that shocked the world' telling the audience is based on a novel and the fact the novel did so well the film will be as good or better and is worth seeing. It helps to persuade the audience to watch it as if they have or haven't read the novel they will know it is a good storyline and lots of people enjoyed it.
At the end of the trailer we heard the main character saying the reason she went somewhere was 'because I'm afraid of myself', which could suggest she went to a mental hospital to get help or stop herself harming people. This suggests she is part of the killing of the woman and makes the audience question everything she said and want to discover what is wrong with her and what really happened. 
The final intertitles that were show are the title of the film as well as the date it is to be released. This is good as after watching the trailer the audience can remember the date so they can go and see the film.