The spelling of English words is problematic for everyone, even native speakers. You just have to learn them, one by one.
Interested in Language
When I hear the native English teacher said that, if people pronoun a word "Apple",
he/she can spell the word "ap" "ple" together with a word "apple".
How can you do that?
How can I improve the spelling?
Here's some alternative spelling of schwa in 'apple'.
I know it's not perfect, but we need some conventions.
***** NOT A TEACHER *****
If you want to improve your spelling, it is absolutely necessary to read, read, read.
When you read widely, your eyes become accustomed to how words are spelled.
Even native speakers, however, must often consult a good dictionary.