The spell checker Spell checkers are a great tool, but we should be careful not to rely 100% on them. At least in Spanish, and other languages with accent marks, there are a lot of words that are not picked by the spell checker because they have more than one meaning just distinguished by these marks. The most common case occurs with the word "mas" - in this form it means "but", however, it is rarely used as such. Instead, the author probably meant to write "más", which means "more". But as you can guess, the spell checker will not hint you any mistake here. Therefore, until a more powerful version arrives, with all these new AI/ML algorithms, we still have to rely on the old yet proved method of slow and careful reviewing.