In Montreal, French is dominant in every aspect of life except when you are in West Island.
So learning French should be the number one priority for most immigrants which is what Quebec officials want you to think or act. But as a new immigrant, your first priority is to fit in, find a stable job to support your family. For most cases, when French may not be the language they are capable of before they landed in Quebec. And most of immigrants come with good professional skills and when they want to find a decent income to keep the living standard of their family. They have to find a job as quickly as possible and often they focus on their professional background and their language skill. Most probably they know English like the rest of the world. And if you know English and have skills, you probably will find a job in Montreal now because at the end of the day, your company needs your skills to provide good products or services not your knowledge of a specific language.
If you work in the field of information technology, English is obviously very important to you. When you are looking for some solutions for your die-hard technical issue, Google is your best friend, not to exaggerate, 90% of times, you can find your answers in English comparing to other language.
After you get your foot steady in Montreal, then it’s the time for French.
That’s my thought on learning English in Montreal as a new immigrant.
Love you, Montreal.