They entered the platform in the first movie . Harry first aked for help from some man and he told them there was no such thing. But He asked Mrs. Weasly later and she told him. That was in the first movie though. I've seen all except the Deathly Hallows.
Dobby. He did this to prevent Harry from going to Hogwarts because he knew about the reopening of the Chamber of Secrets, as being a house elf, to Narcissa and Lucius Malfoy. They did not find that this would hurt them at all since he was just an unimportant slave.
In the second book (Chamber of Secrets) Dobby the house elf prevented them from entering platform 9 and 3/4 because he did not want them to go to Hogwarts.
Dobby
The Hogwarts Express always leaves on the 1st September no matter what day of the week it is.
Remus Lupin and Horace Slughorn both used the Hogwarts Express to travel to Hogwarts. Otherwise, the only adults on the train were the driver and the trolley lady.
Train cars are divided up into compartments.
5972 is the number on the Hogwarts Express shown in the films.
The Hogwarts Express is depicted by a real locomotive built in 1937 by GWR Swindon Works. 5972 is the GWR number of that particular train. You can find more information through the link in related links.
its magic
Hogwarts Express.
It starts in the afternoon (11 am) and gets there at dinnertime.
The Hogwarts Express always leaves on the 1st September no matter what day of the week it is.
To Hogwarts School (Hogsmade, actually); or back to London.
Remus Lupin and Horace Slughorn both used the Hogwarts Express to travel to Hogwarts. Otherwise, the only adults on the train were the driver and the trolley lady.
Dobby did because there is a basilisk (giant snake serfent) and only the air of sliverin (voldimort) can control it
From Kings Cross Stn in London to Hogwarts school of witchcraft and wizardry.
The kids take the Hogwarts Express train to and from school.
It's unknown. Enough to take all the students to Hogwarts.
the hogwarts express
9 & 3/4