One of the problems we have is that similar sounding words may be spelt quite differently. Rough and ruff; meet and meat; great and grate. Words with complicated spelling may be pronounced simply: Leicester is pronounced 'Lester'. Even what rules we do have are frequently broken. ""i" before "e" except after "c"" has over 100 exceptions. Almost all these problems have come about for historical reasons. English has been changing for the last thousand years, and as the language changes, so parts of it get stuck with different spellings.