Question

can you return the book _____ Monday?? preposition​

Answer 1

Answer:

On

Can you return the book On Monday ??

Answer 2

On or by

Prepositions:

Prepositions are the words that are used before any noun, noun phrases (such as to show the direction, place, location, and time), and pronouns. The example of prepositions are "in", "at", "to", "of", "on", etc.

In the given sentence we have to choose the preposition that best fits the sentence.

If we use "on" in the sentence, then,

Can you return the book on Monday?

This means that there is no choice about the day. The book has to be returned on Monday:

Whereas if we use "by" in the sentence, then,

Can you return the book by Monday?

This means that the book can be returned any day.

Hence, both "on" and "by" can be used as per the need of the sentence.