Regular expressions are special characters used instead of unspecified letters and numbers in searches. They can find different words (or strings of characters) which have a common pattern, e.g. words which start the same way, finish the same way or contain certain characters.
This page only gives a few basic examples, please refer to Wikipedia try our regular expressions exercises or this interactive course.
(in simple concordance search only)
Wild cards are not regular expressions but users might be familiar with them form other software. Wild cards are only allowed in a simple concordance search. Only the asterisk (*) and question mark (?) can be used like this:
asterisk (*) stands for zero or more characters
test* will find
test, tests, tested, testing
c*t will find
CT, cut, cat, craft, construct
question mark (?) stands for exactly 1 character
test? will find
tests, Testa, testy
but will not find
c?t will find these lemmas
BUT! simple search always treats each search word as a lemma, thus c?t will search for the lemmas cut, cat and cot. These lemmas will produce results which include all word forms. The final concordance will thus show: cut, cutting, cat, cats, cot, cots, etc.
To search for the asterisk and question mark , use \* and \?
With all the other concordance searches and with wordlists, regular expressions are used in its standard form.
dot ‘ . ‘
A dot stands for a single unspecified character.