One of the difficulties with the English language is that there are often multiple ways to represent the same sound. For example the long a sound can be seen as <ai> as in rain or <ay> as in play. It can also be spelled as just an <a> or in the combination of <a> consonant <e>, such as lane. Then there is the allusive <eigh> as in neighbor or weigh. The process of spelling is hearing a sound, then making a choice on what graphic representation (letter, or letters) will spell that word correctly. Sometimes we choose incorrectly.
There are two methods I use that help with spelling. One is the Orton-Gillingham method. This looks at syllables to determine pronunciation. They are rules, such as <ay> is used at the end of a word, like play, way, say. The other method focuses on looking at the meaning of a word and determining the pronunciation after the meaning is gathered. This method addresses all the words we can "weird" or "rule breakers", the words most people say, "just don't make sense," such as neighbor. We study them as a way to make sense of the English language. Although it often doesn't seem like it, English spelling can be made to make sense.