Let’s use the example sentence: “I like to read.” This is a simple sentence because it only has one subject and verb.
Using a subordinating conjunction and a comma, you could say something like: “I like to read, but only Harry Potter.” As you can see, we used a comma that connects the two independent clauses, and we used a conjunction (but) to connect the two clauses.
To make this a complex sentence, you could say: “When I read, it must be Harry Potter.” At the beginning of the sentence we have a dependent clause, and at the end of the sentence we have an independent clause.
“My dog wanted to play.” “My dog wanted to go to the park afterwards.“ Ok so now u have to add a comma and a conjunction. So now it would look like this “My dog wanted to play, and wanted to go to the park afterwards.” Hope that helped!