四一二事变

the coup of 12th Mar 1927, an attempt by Chiang Kai-shek to suppress the communists / called 反革命政變|反革命政变 or 慘案|惨案 in PRC literature

four / 4

12th April / refers to Chiang Kai-shek's coup of 12th April 1927 against the communists in Shanghai

one / single / a (article) / as soon as / entire; whole; all; throughout / "one" radical in Chinese characters (Kangxi radical 1) / also pr. [yao1] for greater clarity when spelling out numbers digit by digit

one or two; a few / a little; just a bit

two / 2 / (Beijing dialect) stupid

matter / thing / item / work / affair / CL:件[jian4],樁|桩[zhuang1],回[hui2]

incident / unforeseen event / events (in general)

to change / to become different / to transform / to vary / rebellion