Exercise 4: Finding sentence breaks

Finding where one sentence ends and another begins is trickier than might be imagined. Enter a regexp that matches all the items in the first column (positive examples) but none of those in the second (negative examples). When you press "submit", you will see what matched.
Positive Negative
assumes word senses. Within
does the clustering. In the
but when? It was hard to tell
he arrive." After she had
mess! He did not let it
it wasn't hers!' She replied
always thought so.) Then
in the U.S.A., people often
John?", he often thought, but
weighed 17.5 grams
well ... they'd better not
A.I. has long been a very
like that", he thought
but W. G. Grace never had much

Additional Practice

When you have finished the exercises you can now try these techniques on a test file of your own: available here