Canada has two official languages, French and English. In most of Canada, English is the primary spoken language but French is taught in primary schools and is a required subject until Grade 10. It's also on official documentation and on things like product labels. The quality of French education in most of Canada is wildly variable, from immersion programs that produce fluent bilingual speakers to questionable programs that produce people like me.
I am very bad at French. Embarrassingly bad. This is a problem for me, as I live in Quebec.
In the province of Quebec, the largest province in Canada, things are flipped around. Most people learn French as their first language and learn English at school, again with variable degrees of success. The signs are in French. Most documents are in French.
The reasons why this is the case are complicated and still contentious, so I won't go into them.
Bina lives in Montreal, which is in Quebec. Montreal is a very multicultural city, and most people who live there bilingual to one degree or another. Bina speaks French better then I do. Not perfectly, and with a thick Nova Scotia accent, but enough to get by as a waitress in a primarily French speaking city. She also speaks Telugu, the language of Andhra Pradesh.
Kendra, on the other hand, is from northern Quebec and speaks very little English. She stopped taking it in early high-school. She can count up to ten in English, and ask things like "Where is the toilet?" but that's about it.
All of their conversations, so far, have been in French. I just haven't been calling that out, as it's not particularly important.
As to the other characters, Petrovich and Mrs. Hyung both spoke English to Bina, as did Gregor. Gregor doesn't appear to understand French at all.
Piotyr does not speak any human languages because she is a dog. Well… mostly a dog.