The clauses present different relationships between their elements that compose them. These relationships give rise to the so-called syntactic functions of the sentence, as a direct and indirect object , also called direct and indirect complement.
Both complements are related to the action expressed by the verb of the sentence
It is called direct object because it results in the action of the verb in a clear and direct way, while the indirect object performs this action in a secondary way, that is, indirectly.
In the prayer “I told my teacher the truth” we are faced with a direct object (the truth) and an indirect object (to my teacher). The action of the verb falls on the direct object and is secondary to the indirect object.
The first expresses what is said about the subject through the verb. In this way, when one says “Manuel watched a game” the direct object is identified through the question “O que ao verb”, that is, “What did Manuel do?”. In this case, the answer is “watched a game”, so “a game” is the direct object of the sentence.
The indirect object is a modifier that accompanies the verbal head, so we must ask the Who or Who question to the identifying verb. In this way, in the sentence “I prepared a cake for Inês” you must ask the question “For whom did I prepare a cake?” In this case, the answer is “to Ines”. Thus, “for Inês it is the indirect object” and consequently “a cake” acts as a direct object.
Although verb queries are used to identify the complements, this method is not always decisive for detecting the direct object and the indirect object. In this sense, the direct object does not always refer to objects and the indirect object to people.
In the sentence “Luis wrote a poem ,” a poem acts as a direct object, yet a poem could be replaced by the “o”, that is, “Luis wrote it”. In this way, the direct object can be replaced by “o”, “a”, “os”, “as” and really be a direct object. In the prayer “Francis kissed Mary”, Mary is a direct object because we can say “Francisco kissed her”.
In addition to the direct and indirect object, there are also circumstantial complements to the clause
The circumstantial complements are those that describe the way in which a given situation develops.
In the sentence “Today I cut myself with the bread knife twice”, we are faced with three circumstantial complements: “Today” is a circumstantial complement of time, “with the bread knife” is a circumstantial complement of an instrument and “twice” it is a circumstantial complement of quantity.