Note: This entry is for the type of token. For the positional attribute, see word form.
A word is a type of token. All tokens in a corpus are divided into two groups: words and nonwords. Words are tokens which begin with a letter of the alphabet. Tokens such as book, working, Mary, T-shirt, post-1945, mp3 or CO2 are words because they start with a letter.
The regular expression Sketch Engine users to identify words is [[:alpha:]].*
Compare to nonword.