Lesson 30 could not speak / could not have spoken

Choose the correct answers:

  1. When Diana arrived in the United States six months ago, she __________ (could not speak, could not have spoken) English well, so her friends helped her register for an English as a Second Language class.
  2. She __________ (could not have written, could not write) that long essay last semester because it was an assignment from an English 101 course.
  3. She __________ (could not know, could not have known) how to write this essay without taking the course. It must have been written by another student with the same name.


could not + base verb:

unable to do something in the past (inability) or not allowed to do something in the past (without permission)

could not + have + past participle:

impossible that something happened in past (impossibility)

  • In Sentence #1, past inability: Diana was not able to speak English well.
  • In Sentence #2, past impossibility: It was impossible that she was the author because the essay assignment was from another class.
  • In Sentence #3: past impossibility: It was impossible for her to know how to write this essay.



  1. When my daughter Jenny was five years old, I hired my neighbor Magdalena as a babysitter because Jenny __________ (could not stay, could not have stayed) home alone.
  2. Magdalena was a great babysitter. She not only kept Jenny entertained but also taught me how to cook Polish meals.  I __________ (could not hire, could not have hired) a better helper.
  3. Jenny was able to speak a few sentences in Polish.  She __________ (could not learn, could not have learned) it from anyone else but Magdalena.




could not speak; could not have written; could not have known

could not stay; could not have hired; could not have learned