Punctuation: use of dash

[Tom]

Dear friends

i just read in a book:

" In many instances a dash can be used in place of a
comma, semicolon and a colon."

Is it true? If so, I am reasonlessly intimidated by punctuation.

Please guide with a few examples

Yours Tom

[Jamie (K)]

This is true, but it has to be a long dash, not a short one. The dash also indicates that you are trying to put a lot of emphasis on whatever follows, so it doesn't have exactly the same effect as a comma, semicolon or colon. Whatever follows the dash is loud.