1) make the sentences interrogative and negative: a) i have to take a taxi. b) we are able to meet at 5 o'clock. c) you may doit yourself. 2) put the sentences in the past and future tense: a) you must tell us a story. b) we can't go together. c) she may take the book. 3) use modal verbs or their equivalents : a) you do this work now b) i (not) to visit you next sunday, because i to meet my brother. c) as the weather was fine, we to go to the country. d) they use a dictionary during their examp.

1) Make the sentences interrogative and negative:
      a) I don't have to take a taxi. Do I have to take a taxi?
      b) We aren't able to meet at 5 o'clock. Are we able to meet at 5 o'clock?
      c) You may not do it yourself. May you do it yourself?
2) Put the  sentences in the Past and Future Tense:
      a) You had to tell us a story. You will have to tell us a story.
      b) We couldn't go together. We won't be able to go together.
      c) She might take the book. She will be allowed take the book.
3) Use modal verbs or their equivalents :
      a) Could you do this work now
      b) I won't be able to visit you next Sunday, because I have to meet my brother.
      c) As the weather was fine, we would have to go to the country.
      d) They can use a dictionary during their examp.