buy是及物动词，及物动词就是后面直接加名词。buy后面可以直接加名词做宾语，例如：  I bought a beautiful pencil yesterday. buy还可以很双宾语，用法是buy sb sth=buy sth for sb，这里sth是直接宾语，sb是间接宾语。例如： My father bought me a book.= My father bought a book for me.