Question

12. Due to his illness, he could not finish the work-------time.​

Answer 1

Due to his illness, he could not finish the work on time.​

• On is a preposition of time and is used to describe events associated with time.
• For example - Tom went to work on Monday, or They are all lying on your couch.
• In the given sentence, the person was unable to complete his work at a specified time.
• Thus, the correct sentence is - Due to his illness, he could not finish the work on time.​

Answer 2

Answer:

• Due to his illness, he could not finish the work on time.

• 'On' is a Simple Preposition.

• A Preposition is a word which is used before a Noun or a Pronoun and shows its ( noun's or pronoun's ) relation with other words in a sentence.

• Here in the blank space 'on' is showing the function of time. Therefore 'on' is appropriate for the blank space.

• 'On' is used before days of the week, dates and specific days. Examples : on Sunday, on Monday, on the next day, on new year's day, etc.