Usages of duì
这 个 问题 对 他 很 重要。zhè gè wèntí duì tā hěn zhòngyào.
This question is very important to him.
对 我 也 很 重要。duì wǒ yě hěn zhòngyào.
It’s also very important to me.
Elon.io is an online learning platform
We have an entire course teaching Chinese grammar and vocabulary.