He divided the money __________ the two brothers.

The correct preposition to complete the sentence "He divided the money __________ the two brothers" is "between". The choice between "between" and "among" depends on the number of people or items involved in the division or relationship.

• "Between" is used when referring to two distinct people, items, or groups. It emphasizes the individual relationship or division involving exactly two entities. In this sentence, the money is being divided specifically among "the two brothers," clearly indicating two recipients. Therefore, "between" is the appropriate choice.
• "Among" is used when referring to three or more people, items, or groups, especially when they are part of a larger, undefined group or when the distribution is more general. For example, "He divided the money among his children" (implying three or more children).
• "With" implies accompaniment or possession and does not fit the context of dividing something.
• "For" indicates purpose or benefit and is also not suitable for this context.

Thus, the grammatically correct sentence is: "He divided the money between the two brothers." This distinction is crucial for precise communication in English.