title: GREP, command does not work as I've been reading
body: <p>I have given an assignment and the question is:</p>
  
  <p>Suppose you were working a word puzzle and needed a 5-letter word beginning with a vowel (including ‘y’) in upper- or lower-case, a lower-case ‘t’ in the third position, and ending with a lower-case ‘s’.</p>
  
  <p>The remaining letters could be any character that occurs in English words, including upper and lower-case alphabetics, numbers, hyphens, etc. (We will accept the file /usr/share/dict/words as the authority on what constitutes a valid English word and what characters can appear within one.)</p>
  
  <p>What grep command would you use to list the words from /usr/share/dict/words that match this requirement?</p>
  
  <p>I have tried a lot of commands and I can not seem to get it. Is there any kind of hint someone could give me towards the
   answer? </p>