The language in it self is not complicated, except for those words belonging to the sea. They reflect the mind of the main character, in that he is intelligent but unschooled.
The words are written so that they seem translated from the thoughts of a spanish user, and spanish words portrude here and there where the english language falls short of the message.
Hemingway himself said that he only meant to portray reality as best he could, and that the symbols must come later. This however is for the reader to judge.
I'll only leave you with these few word, in hope that you will want to seek out this classic to see for your self. A word of advice: Enter with a calm state of mind and let yourself drift of in your stream of conciousness.
