About half the people in Montreal speak both English and French fluently enough to hold a normal conversation. Another 10–15% speak English as their mother tongue. But that leaves about 35-40% of the population who can't speak English well enough to converse with a native English speaker.

Yes, it is perfectly fine to speak English in Montreal, but understanding the local linguistic etiquette will significantly enhance your experience. Montreal is one of the most bilingual cities in North America; while French is the official language and the first language for many, the vast majority of people in the service industry and downtown areas are fluent in English. A common and polite practice is to start an interaction with a simple "Bonjour-Hi," which signals that you are open to either language. If you continue in English, most locals will seamlessly switch to accommodate you. While you might encounter more French-exclusive environments in the eastern parts of the city or residential neighborhoods, being a respectful tourist who knows basic phrases like "Merci" (thank you) and "S'il vous plaît" (please) is highly appreciated. As long as you aren't rude or demanding about the use of English, you will find Montrealers to be helpful and welcoming.