Why not, assume you might know some French..Ever been to Chinatown in Montreal? The signage there is trilingual--Chinese, English and French. Very cool. And of course, for some Vietnamese immigrants of an older generation, they would know some French already when landing upon North American soil.
Ages ago, I dated a Chinese-Canadian guy originally from Montreal . He could read and write all 3 languages. I'm always totally impressed to meet some (not all) of the Asian-Canadians in Quebec who master all 3 languages.