Most of us agreed that the language is tough and off-putting for the first few letters, but you both get used to the odd spellings and grammar and also the writing gets better at Celie writes more. After eight or ten letters, it all seems pretty normal.
The violence and cruelty is also tough and off-putting in the first part of the book but again, it gets less violent and you get used to it (what a horrifying thought!) as the novel continues.
The words that readers used to describe the events and language in the novel are "epic," "biblical," "powerful," and finally "beautiful."
The story seems huge and the family tree is complicated with parents, step-parents, unacknowledged parents, forced marriages, lovers and mistresses, as well as two dead unnamed mothers. But the major characters are clearly defined and change during the novel and, unlike many novels, the changes are clearly explained and well motivated by events in the novel.

Celie is so desperate to be loved that she loves everyone else without thinking of herself. The men are largely evil (this is probably a valid criticism of the novel) who are forced to learn and change by the strong and far more admirable women who shape them.