A complete sentence is a group of words that conveys a complete idea. Complete sentences must have at least one subject and predicate, the necessary pieces of an independent clause. A subject is the first unit of information and contains a noun; the predicate expands upon that information and contains a verb or phrase. Complete sentences start with a capital letter, and they end with a period, exclamation point, or question mark. \n\nComplete sentences, incomplete sentences, and run-on sentences all convey ideas with varying degrees of information. \n\n- __Complete sentence__: Complete sentences express a complete thought or idea. A complete sentence must have one main clause and a predicate.\n- __Sentence fragments__: Sentence fragments have some information but are incomplete on their own. For example, “Moved south” is an incomplete sentence because it lacks a clear subject. The person reading it would rightly ask “who” or “what” moved south. Fragments may often begin with prepositional phrases, such as “although” and “before.”\n- __Run-on sentence__: Run-on sentences have too much information. Run-on sentences are typically long and have various subjects instead of one main subject. Run-on sentences also contain comma splices. The comma, rather than linking a subordinate clause to the main clause, links together two thoughts that would better be expressed as separate sentences (or as causes of differing importance in a complex sentence). \nWhen writing a complete sentence, begin with a main subject. The subject tells who or what your sentence will be about. Next, follow the subject with a predicate, which offers information about the subject or what the subject is doing. Predicates, which typically begin with a verb, can also link the subject to another noun or verb via a linking verb.\n\nComplete sentences can be long or short, complex or compound, interrogative, declarative, or exclamatory. In any form, complete sentences express a complete thought. Consider the following examples of the complete sentence structure:\n\n1. __“The art thief had a weakness for eighteenth-century masterworks.”__ In this first sentence, the subject or the main noun is “The art thief.” The predicate is “had a weakness for,” which describes something about the subject.\n2. __“My wife has a green thumb, but I can’t seem to keep any plants alive.”__ This sentence has two subjects, the author and their wife. Linking the two subjects together to express a single idea—the comparative abilities of these people with plants—makes it a compound sentence, with the clauses separated by a comma. In the first clause, “has” is the main verb relating to the wife, and in the second, “keep” is the main verb about the author.\n3. __“Every time I hear violin music I cry, which is why I avoid the symphony.”__ In this sentence, there is an independent clause, “every time I hear violin music I cry,” and a subordinate or dependent clause, “which is why,” that further elaborates on the writer’s situation.\nSentences can express statements, questions, commands, or exclamations.\n\n1. __Imperative sentence__: An imperative sentence addresses an implied second person with a request, command, instruction, or invitation.\n2. __Declarative sentence__: A declarative sentence is a sentence that makes a statement, provides a fact, offers an explanation, or conveys information.\n3. __Interrogative sentence__: This type of sentence asks a question and ends with a question mark.\n4. __Exclamatory sentence__: This sentence expresses excitement or emotion, contains a subject, and ends with an exclamation point.\nBecome a better writer with the [MasterClass Annual Membership](https://www.masterclass.com). Gain access to exclusive video lessons taught by the world’s best, including Salman Rushdie, Neil Gaiman, Walter Mosley, Margaret Atwood, Joyce Carol Oates, Dan Brown, and more.\nComplete sentences are made up of a main subject and a predicate.