til 8
This command switches on spell checking:
:setlocal spell spelllang=en_us
This switches on the ‘spell’ option and specifies to check for US English.
The words that are not recognized are highlighted with one of these:
SpellBad word not recognized |hl-SpellBad|
SpellCap word not capitalised |hl-SpellCap|
SpellRare rare word |hl-SpellRare|
SpellLocal wrong spelling for selected region |hl-SpellLocal|
Vim only checks words for spelling, there is no grammar check.