Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Let me give you an example: Context: Architecturally, the school has a Catholic character. Atop the Main Building's gold dome is a golden statue of the Virgin Mary. Immediately in front of the Main Building and facing it, is a copper statue of Christ with arms upraised with the legend 'Venite Ad Me Omnes'. Next to the Main Building is the Basilica of the Sacred Heart. Immediately behind the basilica is the Grotto, a Marian place of prayer and reflection. It is a replica of the grotto at Lourdes, France where the Virgin Mary reputedly appeared to Saint Bernadette Soubirous in 1858. At the end of the main drive (and in a direct line that connects through 3 statues and the Gold Dome), is a simple, modern stone statue of Mary.
Question: To whom did the Virgin Mary allegedly appear in 1858 in Lourdes France?
The answer to this example can be: Saint Bernadette Soubirous
Here is why: This is the correct answer. Because the question is asking for the name of the person and following sentence from the passage answers it: It is a replica of the grotto at Lourdes, France where the Virgin Mary reputedly appeared to Saint Bernadette Soubirous in 1858.

OK. solve this:
Context: English is an important global language, but that doesn't mean it's easy to learn. Many experts have tried to make English easier for students to learn--but they weren't always successful. In 1930, Professor CK Ogden of Cambridge University invented Basic English. It had only 850 words (and just eighteen verbs) and Ogden said most people could learn it in just thirty hours. The problem was that people who learned Basic English could write and say simple messages, but they couldn't understand the answers in "real" English! It was also impossible to explain a word if it wasn't in the Basic English word list. For example, if you wanted a watermelon, you asked for "a large green fruit with the form of an egg, which has a sweet red inside and a good taste"! RE Zachrisson, a university professor in Sweden, decided that the biggest problem for learners of English was spelling, so he invented a language called Anglic. Anglic was similar to English, but with much simpler spelling. "Father" became "faadher", "new" became "nue' and "years" became "yeerz". Unfortunately for some students of English, Anglic never became popular. Even easier is the language which ships' captains use: it's called "Seaspeak". Seaspeak uses a few simple phrases for every possible situation. In Seaspeak, for example, you don't say, "I'm sorry what did you say?" or "I didn't understand, can you repeat that?" It's just "Say again." No more grammar! In the age of international communication through the Internet who knows? ... a new form of English might appear. A large number of the world's e-mails are in English and include examples of "NetLingo" like OIC (Oh, I see) and TTYL (Talk to you later). In another fifty years, English might not exist ... we will probably all speak fluent Internetish!
Question: According to Professor Zachrisson, what was the biggest problem for learners of English?
Answer:
spelling.