During the 60s, he met success with the story for childrem "James and the Giant Peach", gaining both critical and commercial acclaim. Later on (you don’t need the “on”), he published more winning books and a movie about (was made based upon) his book "Charlie and the Chocolate Factory” which was released in cinemas. (Just a technical point here -- he probably didn’t “publish” a movie -- rather, a movie was published based on his book Charlie and the Chocolate Factory).

After suffering a blood dissease, Roald Dahl died in 1990. His 19 children's books and 9 short story stories collection for adults made a magnificent contribution to our literary culture.

Hello Chelo.  You’ve done a really excellent job in describing your topic and Roald Dahl!  Since you obviously have a good command of English, I’ve tried to offer you some suggestions to enhance your writing.  But, make no mistake about it, you write very well!  If any of my edits are confusing to you, please don’t hesitate to send me a message asking for clarification.  Very well done!

The Centenery of Roald Dahl's Birth (in US English, “Centennial” would be more commonly used than Centenary -- I’m not sure about UK English and, according to the definition, Centenary would be correct)

These weeks This week we are celebrating the centenary of Roald Dahl's birth, war hero and one of the greatest British novelists  during the 20th century. Among his most famouse books are Charlie and the Chocolate Factory; James and the Giant Peach; Mathilda; The Big firendly  Friendly Giant; The Witches and The Unexpected Tales. [Unlike in Spanish (and many other languages), in English you’ll find that the titles of books, plays, movies, etc. are capitalized.)

He was born to Norwegians parents near Cardiff, and he was named after the Norwegian polar explorer Roald Amundsene. When he was 3 three (numbers below 10 should be spelled out -- although many people don’t do this!) years old, his father and one of her his sisters died a few weeks apart. Despite experiencing financial issues, his mother decied  decided to stay in GB so her children could study in British schools that she considered the best around (better: in) the world.

His schools days were described with horror. He excelled in sports, and showed some interest in photography; but, he was far to show his excellence in writing.(?? I think you may mean, “He excelled in sports and showed some interest in photography, but he displayed little excellence in writing).   As one of his teachers reported, "I have never met anybody who so persistently writes words meaning the exact opposite of what is intended."

After graduating, he became an explorer, travelling (UK English may spell it with two “l”s but US English would spell it “traveling”)  to different countries such as Iceland, Kenya or Tanzania. During the Second World War, he enrolled in the Royal Air Force as an aircraftman. He was injured and invalided home (perhaps better might be: evacuated home as he was injured). Thanks to his astonishing service records, he was offered to be an assistant attaché to the British embassy in Washington (US).
While in Washington, he wrote his first story for young readers, The Gremlins, (book titles should be underlined -- again, most people don’t do this but it’s the correct thing to do) for Walt Disney. The book didn't success succeed (or: experience success) as expected, so his next books' topics were about dark and macabre topics for adults.

[Part 1 -- Part 2 of edit to follow in another minute -- I’ve reached the iTalki “limit” on words/characters.

This week we are celebrating the centenary of the birth of Roald Dahl. He is considered a war hero and one of the great British novelists of the 20th century. Among his most famous books are “Charlie and the Chocolate Factory,” “James and the Giant Peach,” “Mathilda,” “The Big Friendly Giant,” “The Witches,” and “The Unexpected Tales”.

He was born to Norwegian parents near Cardiff and was named after the Norwegian polar explorer Roald Amundsene. When he was three years old his father and one of his sisters died just a few weeks apart. Despite experiencing financial issues, his mother decided to stay in Great Britain so that her children could study in British schools, which she considered the best in the world.

His school days have been described with horror. He excelled in sports and showed some interest in photography, but he was far from displaying his excellence in writing. As one of his teachers reported, “I have never met anybody who so persistently writes words meaning the exact opposite of what is intended.”

After graduating, he became an explorer traveling to different countries such as Iceland, Kenya, and Tanzania. During the Second World War, he enrolled in the Royal Air Force as a fighter pilot. He became injured and was sent home. Thanks to his astonishing service record, he was offered the position of assistant attaché to the British Embassy in Washington D.C. While in Washington, Dahl wrote his first story for young readers titled “The Gremlins”. It was written for Walt Disney. The book did not succeed as expected, so his next book topics were about dark and macabre topics for adults.

During the 60s, he met success with the children's story “James and the Giant Peach”. It gained both critical and commercial acclaim. He went on to publish more successful books and a movie about his book “Charlie and the Chocolate Factory” was released in cinemas.

Roald Dahl died in 1990 after suffering from a blood disease. His 19 children’s books and 9 short story collections for adults have provided a magnificent contribution to our literary culture.