How do I correctly use accents on acute, grave, and proparoxytone words?

Stressed words are the ones with the stress on the last syllable, and they only get an accent mark when they end in -n, -s or a vowel. For example: "café", "ratón", "compás". If they end in another consonant, they don't get accented: "reloj", "verdad" - wait, "corazón" gets an accent mark because it ends in -n. Unstressed words (or paroxytone words) have the stress on the second-to-last syllable, and here it's the opposite: they get accented when they DON'T end in -n, -s or a vowel. Examples: "árbol", "lápiz", "ángel". If they end in those letters, they usually don't get an accent mark: "casa", "mesa", "libro".

Proparoxytone words are easier because they ALWAYS get an accent on the third-to-last syllable, no exceptions. "Música", "próximo", "matemáticas", "pájaro" - they all get accented. The same goes for words with even more stress back (stress even further back), though they're less common: "explícamelo", "dígaselo".

What really helped me understand this better was practicing while making ingredient lists for my recipes. I spent years writing "azúcar" without thinking about it, but once I started paying attention to why it had an accent mark (proparoxytone, stress on the ú), everything else clicked. The key is figuring out where the stress naturally falls when you say the word out loud, then applying the rules based on what type of word it is.