Frequency Words: “经常(jīngcháng)” vs. “通常(tōngcháng)”

In Chinese, we use “经常(jīngcháng)” or “通常(tōngcháng)” to express frequency. Do you know the differences between the two? Take the following test to have a try! Wǒ zuìjìn _____  jiābān. 我   最近   _____  加班。 I _____ work overtime these days. A. 经常(jīngcháng)

B. 通常(tōngcháng)