Why is spelling difficult?
The simple answer is - because it's difficult. English spelling is not problem-free for anybody. In some languages, like Italian for instance, the sound of a word and the way you spell it are very close, and you pretty much write down what you hear. Also, you can usually tell how to pronounce a word by looking at it. So spelling in Italian is pretty easy. This just isn't so in English.
So, that's the first step - let's agree that spelling is difficult. Everybody who has to write English needs to take care with spelling. That's as true of me as it is of you. It's true that some people find spelling easier than some others, but that's only part of the story. Nobody always gets it right all the time. There aren't any spelling mistakes in this piece of text, but that's not because I'm a naturally brilliant speller. It's because I've taken care over the spelling.
There are some quite complicated historical reasons why English spelling is as hard as it is. If you're interested, you can find out about them from the links in this site. I'm assuming, though, that you're looking at this because you want to improve your spelling, fast, and so that's what we'll look at first.
We'll begin with three common ideas about spelling, all of them wrong. Then we'll look at major spelling mistakes, which are the mistakes that really lose marks. After that, there's a page on common spelling errors, with a test for you, and then pages on American and British spelling. Finally there are some links to other sites about spelling.