Vim's spell checking feature can help discover and correct spelling errors in text. Enabling spell checking: :set spell to enable, :set nospell to disable. Setting language: :set spelllang=en to set English spell checking, :set spelllang=en,cn to set English and Chinese. Spell checking commands: ]s to jump to next spelling error, [s to jump to previous spelling error, z= to view spelling suggestions, zg to add word to dictionary, zw to remove word from dictionary, zug to undo adding to dictionary. Spell highlighting: spelling errors are highlighted in specific colors. Auto-correction: :set spellcapcheck to check sentence capitalization. Spell checking is very useful for writing documents, comments, README and other non-code text, improving text quality. Combined with custom dictionaries, it can handle technical terms and project-specific vocabulary.