How to make some parts of a regex pattern conditional?

Question

I checked this forum for a answer to my problem, but couldnt find. Experts please help.

I have a problem to validate a string say first name. I am given a set of rules w

Answer 1

Try this

[A-Za-z]+(?:[-'!` ]?[A-Za-z]+)?

You can check it online here: regexr

The second part

(?:[-'!` ]?[A-Za-z]+)? 

is a non capturing group, this group is because of the ? at the end optional.