1) Exactly the word "bear" 
Filename      : words.txt
Total lines   : 329359
Total words   : 329359
Regex         : bear
Regex matches : 1

2) Words that contain "bear"
Filename      : words.txt
Total lines   : 329359
Total words   : 329359
Regex         : .*bear.*
Regex matches : 169

3) Words that start with "pre" and end in "ing"
Filename      : words.txt
Total lines   : 329359
Total words   : 329359
Regex         : pre.*ing
Regex matches : 142

4) Three letter words that start and end with a vowel (vowels = aeiou)
Filename      : words.txt
Total lines   : 329359
Total words   : 329359
Regex         : [aeiou].[aeiou]
Regex matches : 181

5) 2, 3 or 4 letter words that start and end with a vowel (vowels = aeiou)
Filename      : words.txt
Total lines   : 329359
Total words   : 329359
Regex         : [aeiou].{0,2}[aeiou]
Regex matches : 707

6) Words then end in one of the following contractions: 'll 're 'nt
Filename      : words.txt
Total lines   : 329359
Total words   : 329359
Regex         : .*('ll|'re|'nt)
Regex matches : 34

7) Social updates that start with "keith is "
Filename      : social.txt
Total lines   : 1000000
Total words   : 10579039
Regex         : keith is .*
Regex matches : 2

8) Social updates that do not contain any vowels (vowels = aeiou)
Filename      : social.txt
Total lines   : 1000000
Total words   : 10579039
Regex         : [^aeiou]+
Regex matches : 13

9) Social updates that consist of three 3-letter words.
Filename      : social.txt
Total lines   : 1000000
Total words   : 10579039
Regex         : ... ... ...
Regex matches : 180

10) Social updates that contain at least one word that is 20 or more characters long.
Filename      : social.txt
Total lines   : 1000000
Total words   : 10579039
Regex         : .*[a-z']{20,}.*
Regex matches : 8

11) All three word social updates.
Filename      : social.txt
Total lines   : 1000000
Total words   : 10579039
Regex         : [a-z']+ [a-z']+ [a-z']+
Regex matches : 40783

12) Social updates that do not contain any vowels.
Filename      : social.txt
Total lines   : 1000000
Total words   : 10579039
Regex         : [^aeiou]+
Regex matches : 13

13) Social updates with 30 or more words where the last word ends in the letter s.
Filename      : social.txt
Total lines   : 1000000
Total words   : 10579039
Regex         : ([a-z']+ ){29,}([a-z']*s)
Regex matches : 2001

14) Social updates containing the word sequence "bowl of cereal" anywhere in the sentence (at the start, in the middle, at the end, or as the whole sentence).
Filename      : social.txt
Total lines   : 1000000
Total words   : 10579039
Regex         : (bowl of cereal .*)|(.* bowl of cereal .*)|(.* bowl of cereal)|(bowl of cereal)
Regex matches : 1781

15) Social updates containing at least one word in which the second-to-last letter is z (the z-word may be in the middle of the sentence or at the end).
Filename      : social.txt
Total lines   : 1000000
Total words   : 10579039
Regex         : (.*[a-z']+z[a-z'] .*)|(.*[a-z']+z[a-z'])
Regex matches : 11553