Modal particles 吧, 了, 吗, 呢
句子 + 吧 / 了 / 吗 / 呢Modal particles sit at the END of a sentence: 吗 turns a statement into a yes/no question, 呢 asks "and what about…", 吧 softens a suggestion, and 了 signals a change of situation.
你这些天忙吗?
Have you been busy lately?
那我们星期天见面吧。
Then let's meet up on Sunday.