v. know and comprehend the nature or meaning of
v. perceive (an idea or situation) mentally
v. make sense of a language
v. believe to be the case
vt. 理解, 了解, 领会, 听说, 懂
vi. 懂得, 认为
1. I don't understand this math problem.
我不理解这个数学题。
2. Can you explain it again so I can understand?
你能再解释一遍，让我明白吗？
3. It's important to understand other people's feelings.
理解他人的感受是很重要的。