All the words that we use in our language to express ourselves have a syllable on which it falls accentuation, meanwhile, formally it is called as stressed syllable.
Although it does not happen with all words, the accent or spelling accent is the one that will be placed in them to effectively indicate that accentuation they carry.
For example, when we see the tilde we will know that we must give that word an intonation pronounced in the syllable that has it.
There are several accentuation options that we can find in our language, however, it is important that we emphasize that the most common is that the words are stressed on the last or penultimate syllable, such is the case of high-pitched words and low-pitched words, respectively.
We must clarify that our language is mostly made up of words accented in the penultimate syllable stressed, that is, of serious words.
The grave word, then, will be the one that bears the accent on the penultimate syllable, being the most common that they end with the consonants n or s or with any of the five vowels (a, e, i, o, u). Meanwhile, the accent will only be placed in the event that the grave word culminates in a consonant other than the aforementioned s or n, preceded by vowels, or failing that in two consonants. Tree, album, leaf, are some examples of serious words.
But as we already indicated above lines, the possibilities of accentuation are more than one, that is, not only are the serious words, there are also the sharp words, words esdrújulas and sobreesdrújulas.
Sharp words are the ones that follow in amount of presence to serious words in our language. In this case the accentuation occurs on the last syllable.
On the other hand, the words esdrújulas, another of the accentuation options, have the accent on the penultimate syllable. This type of accentuation is not so common and therefore there are not so many words of this type in relation to the bass and treble. A characteristic feature is that they never go without an accent.