The first word is 了解 (liǎo jiě) which is a verb that means to understand. A way of using it in a sentence is 我不了解这件事。(Wǒ bù liǎojiě zhèjiàn shì.) I don’t understand this matter.
解决 (jiě jué) To solve
Another word we can create with 解 (jiě) is 解决 (jiě jué). This is a verb that means to solve. Let’s again look at each character of this word, 解 means solution and 决means to decide. A way of using it in a sentence is 我明白怎么解决问题。(Wǒ míngbái zěnme jiějué wèntí.) I know how to solve this problem.
解释 (jiě shì) To explain
Finally, we can create the word 解释 (jiě shì) which means to explain. A way of using it in a sentence is 你能解释一下这个问题吗？(Nǐ néng jiěshì yīxià zhège wèntí ma?) Can you explain this question?