Besides the well-known general rules to put accents in Spanish, in 2010 the Royal Academy of the Spanish language (RAE, for its initials in Spanish) released “La Ortografía de la lengua española” (The Spanish Language Ortography), to describe the ortographic Spanish language system and explain its main rules for the correct writing in Spanish. As a review, here we mention a couple of those rules:
1. Monosyllabic words do not have tilde (accent), except when the tilde is needed to differentiate a word from another one that has different meaning (diacritic accent). For example: tú (you) – tu (your); él (he) – el (the); mí (me) – mi (my); si (if; oneself), sí (yes); té (tea) – te (personal pronoun “you“, i.e.: ‘yo te dije’ – ‘I told you‘); dé (subjunctive form of verb ‘dar‘ – to give – for the 1st and 3rd person singular) – de (of); sé (I know; ) – se (3rd person singular/plural personal pronoun, i.e.: ‘ellos se aman‘ – ‘they love each other‘; or personal pronoun to form impersonal and pasive voice sentences, i.e.: ‘se busca vivo o muerto‘ – ‘wanted dead or alive‘).
2. Words such as the adverb ‘solo’ (only) and the demonstratives ‘esta, este, esto’ (this) do not need to have the diacritic accent anymore. In the 2010 rules of the Spanish language ortography, the RAE “adviced” that Spanish speakers did not neet to put the diacritic accent in words such as ‘solo’ (only; alone) and ‘esta, este, esto’ (and their plural forms: estas, estos). However, it has been noticed that users continue to put accents on these words to distinguish words as it follows:
‘solo‘ (alone) / ‘sólo‘ (only)
‘esta, este, esto’ (demonstrative adjectives; i.e.: ‘esta casa’ – ‘this house’) / ‘ésta, éste, ésto’ (demonstrative pronouns; i.e.: ‘esta casa es nueva, pero ésta no‘ – ‘this house is new, but not this one‘).
Personally, since this advice was released, I have stopped putting accents on the #2 cases, as I believe the context clarifies the meaning of the word, avoiding possible confusion. However, as Salvador Gutiérrez, one of the members of the RAE mentioned, I have noticed that some writers continue keeping the diacritic accent in those cases. I would like to hear what other people think about it.
For further resources visit: http://www.rae.es/obras-academicas/ortografia/ortografia-2010