快速答案
degradar 表示使退化、恶化；degredar 表示判处流放。
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
degradar
to degrade or deteriorate
Use degradar for lowering quality, dignity, rank, or environmental condition.
degredar
to exile or banish
Use degredar for condemning someone to forced residence away from their home.
如何选择
- degradar: Choose degradar if the sentence points to lowering quality, dignity, rank, or environmental condition.
- degredar: Choose degredar if the sentence points to condemning someone to forced residence away from their home.
例句
O descarte irregular degradou o rio.
Illegal dumping degraded the river.
A antiga sentença mandava degredar o condenado.
The old sentence ordered the convict into exile.
常见误区
Degredar is mainly historical or legal-literary today. Degradar is the current verb for deterioration and humiliation.
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 degradar，一次用 degredar。如果两个版本都可以，说明意思怎样变化。