What is the difference between begin and start?

[shivanimt]

Dear Madam,

I need your help on the following.

What is the difference between begin and start?

When can we use begin and when can we use start?

[Lucy]

Dear Shivanimt,

Start and begin are mostly interchangeable. In the following sentences begin cannot replace start:

When planning a journey: “what time shall we start?”

Seeing my old schoolfriend again started me thinking about the old days.

The reasons are which words collocate with which verb.

Kind regards,

Lucy