Introduction

The correct preposition to use in the given sentence is "for". The sentence should read, "He did not speak to his brother for many years." In this response, we will discuss the usage of the preposition "for" and explain why it is the appropriate choice in this context.

Explanation

The preposition "for" is used to indicate a period of time in this sentence. It is commonly used to express the duration of an action or event. In this case, the sentence implies that the speaker and his brother have not had any communication or conversation for a long period of time.

The word "since" is not suitable in this context because it is used to indicate a specific point in time when an action or event began. It is typically used with a specific date, year, or moment. For example, "He has not spoken to his brother since 2010." The use of "since" implies that there was a specific event in 2010 that caused the lack of communication between the two individuals.

On the other hand, "for" is used to express a duration of time without specifying a starting point. It indicates that the action or event has been ongoing for a particular length of time. In this sentence, the speaker is emphasizing the long duration of time during which he and his brother have not spoken.

Summary

In summary, the correct preposition to use in the given sentence is "for." The preposition "for" is used to express a duration of time, while "since" is used to indicate a specific starting point. By using "for," the sentence conveys that the lack of communication between the speaker and his brother has lasted for many years.

A long time