on parle anglais,on comprend americian

on parle anglais,on comprend americian
请问具体怎么理解,是指说英语的人就能听懂美国人说话吗?前文提到了the fact that americans and the english speak differently seem to have been noticed by the shopkeepers of Paris who have both peoples as their customers.之后提到一个朋友在巴黎店里看到的一张告示上写了这句话,”on parle anglais,on comprend americian“.最后提到,法国人在商业方面天赋不强,但这个店老板挺聪明的.