The weirdness of English, item 569

If you ever get the blues Buy yourself a pair of shues!

If you ever get the blues

Buy yourself a pair of shues!

The spelling in our language is so irregular that I wonder how learners cope with it. Sch is pronounced 'sk' as in 'school', except in Britain where it becomes 'sh' in the word 'schedule'. Why? In any case, we need 'sh' to signify a kind of dental sibilant fricative (if I've got that right), except when it comes to 'sugar', which is simply given an S without the H. Again, why? (The French have 'sucre' and they pronounce it as you would expect, as in 'Susie'.) And then, on the subject of words beginning in 'sh', why is 'shoe' so spelled? Wouldn't you expect a word ending in 'oe' to sound like a long O (as in hoe, roe, sloe, doe)? Why isn't 'shoe' spelled 'shoo' or 'shue'? What a strange language this is!