Summarize this article in one sentence.
At minimum, every sentence consists of a subject and an action. A sentence that lacks either one is a sentence fragment and is considered to be improper.  The subject is usually a noun or pronoun, and the action is conveyed using a verb. Correct example: The dog ran. Note that the subject is indicated in italics and the action is indicated in bold print.  Incorrect example: Yesterday afternoon. Expand your sentences into more complex forms after mastering this basic format. Within a sentence, both the subject and verb must share the same singular/plural state. You cannot use the singular form of a verb with a plural subject; a plural subject must have a plural verb.  Correct example: They are at school. Incorrect example: They is at school. When two singular subjects are connected with the word "and" (he and his brother), the subject becomes plural. When connected by "or" or "nor" (he or his brother), the subject is singular. Collective nouns, like "family" or "team," are treated as singular nouns and require a singular verb. Compound sentences are the easiest sentence form to master after the basic sentence. Use a conjunction to join two related thoughts into one sentence rather than forming two separate sentences.  Instead of: The dog ran. He was fast. Use: The dog ran and he was fast.  Instead of: We looked for the missing book. We could not find it. Use: We looked for the missing book but could not find it. A conditional sentence describes a situation in which one part of the sentence is true only if the other part is true. They can also be referred to as "if, then" statements, but the word "then" will not always appear when the sentence is written. Example: If you ask your mother, then she will take you to the store.  Note, however, that it would also be correct to write: If you ask your mother, she will take you to the store. Both forms are still conditional. Use clauses to form complex sentences. Clauses are the "building blocks" that can be used to expand a sentence past its basic form. They can either be independent or dependent.  An independent clause has its own subject and verb. As a result, it could stand as its own sentence. Note that compound sentences, as mentioned previously, consist of independent clauses.  Example: She felt sad, but her friends cheered her up.  Both "she felt sad" and "her friends cheered her up" could stand as separate sentences.   A dependent clause is one that could not stand as its own sentence.  Example: While he agreed with his brother, the boy would not admit to it.  The clause "While he agreed with his brother" would not make sense a separate sentence, so it is a dependent clause. There are multiple punctuation marks and various rules governing their usage. You should study these rules in detail, but first, you need a basic understanding of how each punctuation mark is used.   Periods (.) mark the end of a statement sentence.  Ellipses (...) indicate that a portion of text has been removed from the passage.  Commas (,) separate words or word groups when a pause is necessary but a period is inappropriate.  Semicolons (;) should be used in complex sentences that lack a connecting conjunction.  Colons (:) are used to introduce lists within a sentence.  Question marks (?) are used at the end of a sentence when the sentence asks a question.  Exclamation points (!) are used at the end of a statement sentence to indicate surprise or emphasis.  Quotation marks (") separate words spoken by another person from the rest of the text.  Parentheses () enclose information that clarifies a preceding thought.  Apostrophes (') separate contractions and show possession.

Summary:
Learn how to structure a basic sentence. Maintain correct subject/verb agreement. Form compound sentences. Practice using conditional phrases. Understand how to use clauses. Manage punctuation.