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.