By using regex expression:
1.How many words with four letters
2.How many words with at least two vowels and the vowels neednot be adjacent.
Answer
Regex expression with only 4 letter word
/^[a-z]{4}/i
words with at least two vowels and the vowels need not beadjacent
[^aeiuo][a,e,i,o,u][^aeiuo][a,e,i,o,u]