The following sentence has been divided into parts. One of them may contain an error. Select the part that contains the error from the given options. If you don't find any error, mark 'No error' as your answer.
By the time she retires, / she has been teaching / at the university for 30 years.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. she has been teaching.
Error Concept: Tense inconsistency in a future time reference.
What is wrong: The use of “has been teaching” (present perfect continuous) is incorrect in the context of a future reference “By the time she retires.”
Grammar Concept: When referring to the duration of an action up to a point in the future, we use the future perfect tense or future perfect continuous tense, not present perfect continuous.
Incorrectness of the concept in context: The phrase “By the time she retires” refers to a future moment. So, we must express the ongoing nature of the action (teaching) up to that future point using future perfect continuous tense: will have been teaching.
Correction: Thus, “has been teaching” should be replaced with “will have been teaching”.
Corrected phrase: will have been teaching
Final sentence: By the time she retires, she will have been teaching at the university for 30 years.
Hence, the chosen option is correct.