Installing a dictionary add-on will add a new language option to your spell-checker, which checks your spelling as you type in Firefox.
We nayäk jun soltzij xtitz'aqatisäx jun k'ak'a' cha'oj pan ruchojmirisanel ach'ab'äl, ri xtunik'oj atz'ib'anikil toq xkatz'ib'an pa Firefox.