Regex to match first word in sentence

Question

I am looking for a regex that matches first word in a sentence excluding punctuation and white space. For example: \"This\" in \"This is a sentence.\" and \"First\" in \"First,

Answer 1

(?:^|(?:[.!?]\s))(\w+)

Will match the first word in every sentence.

http://rubular.com/r/rJtPbvUEwx