Considering, "The BFG" was one of Roald Dahl's best books. The story is strong, humourous in places, and it makes sense. The only problem is that there are many plotholes.
Okay...the story begins when a little orphan girl called Sophie looks out of her window one night...and sees a giant. He realizes that she has spotted her, and he decides to basically kidnap her, so his existance is kept secret. So he takes her away to his home-she gets scared-and then they start conversing. Sophie finds out that the giant is the only one known that does not fend on humans, and has the name "Big Friendly Giant" shortened to BFG. The two become friends and they come up with an idea to save future victims of human-eating giants.
Now plotholes: 1. Did anyone care when Sophie disappeared? 2. There are a few meaningless lines that contradict what happens. 3. Why did Sophie get to live in her own house when she turned up in London? What about the orphanage? She's only eight years old, as she says in one chapter.
In all, it's a great book for kids. Just don't read too much into the logic. I've loved this book for years, and I think others will love it too.