Why is English the most widely spoken language in the us and Canada today?

Answer:

Because aviation required a common language for safety as it became a common an commercial means to travel.

Answer:

The English-speaking countries, taken together, have about 400 million native speakers. Nearly all these countries are prosperous; they are well spread around the world - and of course they include the world's only real super-power, the US.

Answer:

it is known and used widely in everyday life and business.

Answer:

In adition to the previous answers, Hollywood had a large role in making English an international language. American TV and movies spread throughout the world, starting as early as the 1930's.