“了”用在动词或形容词后面，表示动作已经完成，或者情况发生了变化。
“le” yòng zài dòngcí huò xíngróngcí hòumiàn, biǎoshì dòngzuò yǐjīng wánchéng, huòzhě qíngkuàng fāshēngle biànhuà.
The particle “了” is placed after a verb or adjective to show that an action has been completed or a situation has changed.
了用在动词后面，表示动作已经做完了，或者事情发生了变化。它常常出现在日常生活的对话里。
le yòng zài dòngcí hòumiàn, biǎoshì dòngzuò yǐjīng zuò wán le, huòzhě shìqíng fāshēng le biànhuà. tā chángcháng chūxiàn zài rìcháng shēnghuó de duìhuà lǐ.
了 is placed after a verb to show that an action is finished or a situation has changed. It is very common in everyday conversations.
了 shows a completed action; 过 emphasizes having had an experience. 我吃了 (I ate) vs 我吃过 (I have eaten it before).
了 marks completion; 着 marks a continuing state, like 坐着 (sitting).