Which verb cannot be directly followed by a pronoun without a preposition?

The verb that cannot be directly followed by a pronoun without a preposition is "explain." This verb requires a more structured sentence where additional elements are necessary to clarify the relationship between the verb and its object. In standard usage, "explain" is commonly followed by a noun or a noun phrase that specifies what is being explained, and if a pronoun is used, it typically requires a preposition, such as "to." For example, you would say "explain it to him" rather than just "explain him."

In contrast, the other verbs listed, such as "advise," "tell," and "recommend," can be used with pronouns directly. For instance, one might say "advise him," "tell her," or "recommend it," demonstrating that these verbs can appropriately link to a pronoun without necessitating an additional preposition. Thus, understanding how certain verbs operate with pronoun usage is essential for constructing grammatically accurate sentences.