Begin or start?   Grammar > Easily confused words > Begin or start? from English Grammar Today We can use the verbs begin and start to mean the same thing but begin is more formal than start. Begin is an irregular verb. Its past simple form is began and its -ed form is begun: When did you begin learning English? The meeting didn’t start until 9 pm. We use start, but not begin, to talk about machines: Press this button to start the printer. Not: …to begin the printer. The lawnmower won’t start. (this means that it doesn’t work) Not: The lawnmower won’t begin. Start, but not begin, is used to talk about creating a new business: She started a new restaurant and it’s been going really well. Not: She began a new restaurant …  according to Cambridge

It's acceptable to use either choice, there is no clear rule, but "start" is used more often and in most informal contexts. You would also usually "begin" a structured task such as a test, a meal, a phonecall, a race, and anything else which happens in a limited time and is completed soon.

Hello, in many cases they are interchangeable, but begin is more formal than start. Another difference is that "start" means to activate or enable something, ex "start a car".