We can classify spelling errors into three types:
Typing errors, simple typographical errors that occur when you press a key wrongly.
Confusion between similar words (homonyms) but that have different meaning
Missing tilde (orthographic accents).
The spelling checker of the word processor identifies words that do not exist as incorrect (for example, hiba instead of iba) but does not find errors when a well-written word is used incorrectly (for example, there is instead of found). The same thing happens with some words or phrases that ‘sound’ like others that also exist but that have different meaning (for example, it consists of two parts instead of consisting of two parts). In Spanish, there are homophones that are often confused, such as a-ha, vaso-spleen, boil-sew, enzyme-enzyme, haya-halla, or bone, tube-had, beautiful-hair, basket-sixth, cent -I feel, e-he, you-do, months-memes, wise-sap, rate-cup, have-see, see-time, you-voice. In these cases, the spell checker will not detect the error either.
The spell checker identifies badly accented words when they do not exist in the language (for example, emulsion, protein, nucleus) but can not detect them if the same word can be written with or without a tilde according to its meaning, such as: practical-practical- practiced, practice-practice, practice-practices, course-attended, what-what, towards-did, would-be, chapter-chapter, English-English, number-number-number, page-page, term-term-ended, etc.
So … you have to know spelling and accentuation!