This question tests the rules for turning direct speech into indirect (reported) speech. The original sentence is: Suresh said, "I did it yesterday." Three changes are needed here: the tense inside the quote must shift back one step, the pronoun "I" must switch to match the subject "Suresh", and the time word "yesterday" must change since we are reporting it later. Let's check each option against these three rules.
- Suresh said that I did it yesterday.: The pronoun "I" is left unchanged even though Suresh is being talked about in the third person, the verb "did" is not shifted back to "had done", and "yesterday" is left as is. None of the three required changes are made.
- Suresh says I did it yesterday.: The reporting verb is wrongly changed from "said" to "says", turning it into the present tense, and the tense inside the quote and the time word are also left unchanged.
- Suresh says that he did it the day before.: The pronoun and the time word are handled correctly here, "he" and "the day before" are both right, but the reporting verb is still wrongly written as "says" instead of "said", and "did" is not shifted to "had done".
- Suresh said that he had done it the day before.: The reporting verb "said" is kept in the past tense as in the original, "did" correctly shifts back to "had done", the pronoun becomes "he", and "yesterday" becomes "the day before". All three rules are satisfied.
Since the original reporting verb "said" is already in the past tense, it stays "said" in the indirect version too, it is only the verb reported inside the quote that shifts further back to the past perfect. That single distinction is what separates the correct option from the three incorrect ones.
Let's summarize:
- A past-tense reporting verb like "said" does not change to "says" or "said" plus "to" in reported speech, it stays "said".
- The verb inside the quote shifts one tense back: simple past becomes past perfect.
- Pronouns and time words like "yesterday" change to fit the new speaker and the new time of reporting.
The correct indirect form is "Suresh said that he had done it the day before", which is option (D).