快速答案
isto、isso 和 aquilo 不修饰名词，分别指这里、听话者那里和更远处的事物。
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
isto
this thing or idea
Use isto for an unidentified thing near the speaker or an idea being introduced.
isso
that thing or idea
Use isso for an unidentified thing near the listener or something already said.
aquilo
that thing over there
Use aquilo for an unidentified thing far from both people.
如何选择
- isto: Choose isto if the sentence points to an unidentified thing near the speaker or an idea being introduced.
- isso: Choose isso if the sentence points to an unidentified thing near the listener or something already said.
- aquilo: Choose aquilo if the sentence points to an unidentified thing far from both people.
例句
O que é isto?
What is this?
Isso é verdade.
That is true.
Aquilo é uma igreja.
That over there is a church.
常见误区
These forms do not change for gender or number. Before a named noun, use este, esse, or aquele instead.
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 isto，一次用 isso。如果两个版本都可以，说明意思怎样变化。