Last week I had a wonderful reminder that we should never assume that people don't understand what we are saying in English.
I was taking the Line 13 subway train from Dongzhimen, near my apartment, up to Wudaokou, the university and technology hub of Beijing. It was crowded when I got on but I was able to get a seat and started reading, glad for the comfort of the air-conditioning in this ridiculous heat wave. After a few minutes I heard two people speaking English but ignored it...until I heard the woman say "You look so good in that T-shirt, I could totally do you." Her tone was pure comedy, and it caught my attention. As I started to laugh they both looked over, appalled to realize that they weren't the only foreigners on the train.
Nice couple. They were going to the same station so we chatted the rest of the way, about life in China, politics, language...and never assuming that people won't understand what you say.