A sentence is composed when two verb forms appear in its statement (contrary to the simple sentence that only has one). Let's look at several examples of compound sentences:
"He read the novel and was satisfied."
"I am concerned about the opinion that people have."
"They want me to leave office."
In all three examples, each sentence has two distinct parts that are combined with each other and each part is known as a proposition. The grammatical combination of each proposition can be done in three different ways: by coordination, juxtaposition or subordination.
Coordinate compound sentences
The main characteristic of these sentences is that they are on the same syntactic plane, that is, they have the same rank and, in addition, they are united by a link or nexus. Let's look at three concrete examples:
"My team has won the game but it is not the champion."
"I got home early and made dinner."
"My friend studies and his cousin works."
There are several possibilities for coordinated compound sentences, depending on the type of nexus that joins them. On the one hand, the copulative (The friend plays and his cousin reads). There is also the dilemma (Give me the money or leave). The distributive compound sentence (It's raining here, it's sunny there). The adversative (I won the game but I was not satisfied). Finally, the explanatory compound sentence (He is a very young worker, that is, he has no experience).
Juxtaposed compound sentences
In these sentences, there is no word that acts as a connecting link, but rather a punctuation mark that relates the two parts of the compound sentence. Again we illustrate this explanation with some examples:
"It's very cold, I'll put my coat on."
"There is a great concern: the danger is imminent."
Subordinate compound sentences
The fundamental characteristic of these sentences is the dependency relationship of one part with respect to the other. In other words, there is a main sentence and another that is subordinate. Let's see it with two concrete examples:
"He said to get there as soon as possible."
"I wonder if he will come next weekend."
Compound sentences in which there is a subordination are presented, in turn, with three different modalities: adverbial subordination (I will do it when I can), substantive subordination (he told me that he would not do it) and adjective subordination (students who they suspended they left so happy).
