人微言轻 The person is low, so the words are light. What a person of low position says is not taken seriously. Su Shi used the phrase in a letter: “I have reported this matter three times and have had no reply. The person is low and the words are light, so it is only natural.”
插嘴 To insert a mouth. To speak before another person has finished.
打官腔 To strike the official tone. To answer with official set phrases in order to put someone off.