Begin vs Start

The verbs Begin and Start are virtually interchangeable, and both verbs can be transitive or intransitive, but Start is commonly used in spoken English.  

• It started/began to snow. [=It started/began snowing.]
• When I gave her the bad news, she started/began to cry.
• I got a job at a hotel and I begin/start work on Monday.
• I started/began (reading) this book a few days ago.
• When did the concert begin/start?
• The word ‘animal’ begins/starts with the letter ‘a’.

Begin

Begin is an irregular verb; its three forms are begin, began, begun. Begin is a little more formal than Start.

• Let us begin the meeting by reviewing the results.

We use Begin to mean ‘to start speaking’.

• ‘Good evening everybody’, he began, ‘Welcome to the show’.
• ‘Good evening everybody’’, he started,…
• I don’t know how to begin.

Start

Start is a regular verb; its three forms are start, started, started.

Start, but not Begin, is used to mean ‘to create a business or organization’.

• I decided to start a retail shop.
• …to begin a retail shop.
• He started his own company after graduating from college.

Start, but not Begin, is used to mean ‘to switch on a machine or engine’ or ‘to make them work’.

• He started the car and drove home.
• He began the car…
• At last the car started.

We can use ‘off’, ‘up’ or ‘out’ after Start.

• She started up her own small business.
• The car won’t start up.
• We’ll start the meal off with chicken soup.
• The day started out beautifully.

Synonyms

Commence (formal) and Kick off (informal) are the other verbs that mean ‘to start or begin’

• She commenced her teaching career in New York.
• The contract commences on the first day of the fiscal year.
• Tonight's game kicks off at 3 pm.

In summary, there is not a significant difference between Begin and Start, and they have almost the same meaning, but Begin is not possible to use in some cases.