"I go to work on 8 a.m." The usage of the preposition 'on' is incorrect. Find the correct preposition to be used in this sentence.

Words that usually precede nouns or pronouns and express their relation with other parts of the sentence are known as prepositions. Prepositions can be of several types, depending upon their usage. To refer to a point in time, prepositions of time are used. The usage of the preposition 'on' is incorrect in the question statement. The preposition 'at' will be used instead. Thus, "I go to work at 8 a.m." is the grammatically correct statement.