Final answer:
A simple sentence contains one main clause, a compound sentence joins two or more main clauses with coordinating conjunctions, a complex sentence combines a main clause with one or more subordinate clauses, and a compound-complex sentence has at least two main clauses plus one or more subordinate clauses.
Step-by-step explanation:
In English grammar, there are different types of sentences that can be used to convey various kinds of information and ideas. A simple sentence consists of a single main clause with one independent idea, and can vary in length. For example, 'The coronavirus spread around in the world in 2020' is a simple sentence because it expresses a complete thought with one clause. Compound sentences are formed by joining two or more main clauses that are of equal importance, usually with a coordinating conjunction, such as 'for', 'and', 'nor', 'but', 'or', 'yet', or 'so'. An example of a compound sentence is, 'This peach is way beyond ripe, and I refuse to pay for it', which connects two independent clauses with the conjunction 'and'.
A complex sentence contains one main clause and one or more dependent (subordinate) clauses. For instance, 'She is going to be a schoolteacher because she believes education is the most fundamental pillar of the republic' demonstrates a complex sentence with its single independent clause and a subordinate clause introduced by 'because'. Lastly, a compound-complex sentence merges the elements of both compound and complex sentences, containing at least two main clauses and one or more subordinate clauses. Their purpose is to express multiple ideas within the same sentence efficiently.
Understanding the difference between these sentence structures is critical for effective writing and can impact the tone, mood, and clarity of the prose. Narrative and other forms of writing rely on varying sentence types to maintain interest and convey complex information comprehensibly.