快速答案
acento 与发音和书写重音有关；assento 指座位或正式记录。
可靠的方法是先判断这个词在句子里的功能，再翻译。
每个词的作用
acento
accent mark, stress, or accent
Use acento for a written diacritic, emphasis on a syllable, or a characteristic way of speaking.
assento
seat or official record
Use assento for a place to sit or a written entry in an official register.
如何选择
- acento: Choose acento if the sentence points to a written diacritic, emphasis on a syllable, or a characteristic way of speaking.
- assento: Choose assento if the sentence points to a place to sit or a written entry in an official register.
例句
A palavra “você” leva acento circunflexo.
The word “você” takes a circumflex accent.
Meu assento fica perto da janela.
My seat is near the window.
常见误区
They are homophones in most of Brazil. Meaning—not sound—decides whether the spelling begins with ac or ass.
放到语境中练习
从你的真实生活中选一个句子，写两遍：一次用 acento，一次用 assento。如果两个版本都可以，说明意思怎样变化。