Learning English spelling words is not always an easy task. English spelling can be especially challenging for those learning English as a second language. One reason spelling Engilsh words is so complicated is that many words are not spelled as they sound when they are spoken. Another issue is that some words sound the same, but depending on the meaning, they can be spelled completely differently.
An example of a word that is pronounced the same but spelled differently would be the words to, too, and two. You could say, "I am going to the store, do you want to come too, we can buy two cokes." Two is referencing the number "2," and too is when you mean "also." Another example is the word there--you could also mean their, or they're. Their is a possessive word, as in that is their car. They're would be used for they are, and finally there, as in, I want to walk over there.
A letter combination that is difficult for both native English speakers and those learning English as a second launguage is "ough." These letters look the same but can be pronounded differently depending on the word. Tough, is pronounced tuf, bought sounds like bawt, and dough is doe. The same letters, but completely different sounds.
The reason English is so difficult is because the English language has taken words from many different languages, some spellings were changed and some were not. The rules to spell and learn them will do much to help one learn to spell, just be aware that most English spelling rules do have exceptions and many words have silent letters. When learning spelling, it's a good idea to write down spelling rules and also write down hard to spell words. As they say, practice makes perfect and that is very true in spelling. Many native English speakers learn spelling as children by writing down a particular word over and over. While spelling English words can be difficult, it's not impossible, it just takes some help and some practice.