Parts of Speech and Sentence Structure

Nouns: Names of people, places, things, or ideas (e.g., cat, city, happiness).
Pronouns: Words that replace nouns (e.g., he, she, it, they).
Verbs: Action or state of being words (e.g., run, is, think).
Adjectives: Words that describe nouns (e.g., blue, quick, tall).
Adverbs: Words that modify verbs, adjectives, or other adverbs (e.g., quickly, very, well).
Prepositions: Words that show relationships between nouns/pronouns and other words (e.g., in, on, at).
Conjunctions: Words that connect clauses or sentences (e.g., and, but, or).
Interjections: Words that express emotion (e.g., wow, ouch, hey).

Simple Sentence: Contains one independent clause (e.g., She runs).
Compound Sentence: Contains two or more independent clauses joined by conjunctions (e.g., She runs, and he swims).
Complex Sentence: Contains one independent clause and one or more dependent clauses (e.g., When she runs, she feels happy).
Compound-Complex Sentence: Contains at least two independent clauses and one or more dependent clauses (e.g., When she runs, she feels happy, and he swims).

Present Simple: Used for habitual actions (e.g., She walks).
Present Continuous: Used for ongoing actions (e.g., She is walking).
Past Simple: Used for completed actions (e.g., She walked).
Past Continuous: Used for actions that were ongoing in the past (e.g., She was walking).
Future Simple: Used for actions that will happen (e.g., She will walk).
Present Perfect: Used for actions that occurred at an unspecified time (e.g., She has walked).

Active Voice: Subject performs the action (e.g., The cat chased the mouse).
Passive Voice: Subject receives the action (e.g., The mouse was chased by the cat).

Run-On Sentences: Two or more independent clauses joined incorrectly.
Sentence Fragments: Incomplete sentences lacking a subject or verb.
Misplaced Modifiers: Words or phrases that are incorrectly placed, leading to confusion.

Nouns identify people, places, things, or concepts (e.g., cat, city, happiness).
Pronouns substitute for nouns to avoid repetition (e.g., he, she, it, they).
Verbs express actions or states of being (e.g., run, is, think).
Adjectives provide descriptions for nouns, adding detail (e.g., blue, quick, tall).
Adverbs modify verbs, adjectives, or other adverbs, often indicating how, when, or to what extent (e.g., quickly, very, well).
Prepositions illustrate relationships between nouns/pronouns and other elements in a sentence, often indicating location or direction (e.g., in, on, at).
Conjunctions link clauses or sentences, helping to form complex ideas (e.g., and, but, or).
Interjections convey emotions or sentiments, often sudden (e.g., wow, ouch, hey).

A simple sentence consists of a single independent clause (e.g., She runs).
A compound sentence features two or more independent clauses connected by conjunctions (e.g., She runs, and he swims).
A complex sentence includes one independent clause and at least one dependent clause (e.g., When she runs, she feels happy).
A compound-complex sentence combines multiple independent clauses with at least one dependent clause (e.g., When she runs, she feels happy, and he swims).

Present simple tense indicates habitual actions or facts (e.g., She walks).
Present continuous tense denotes ongoing actions occurring at the moment (e.g., She is walking).
Past simple tense reflects actions that have been completed (e.g., She walked).
Past continuous tense describes actions that were in progress during a specific past time (e.g., She was walking).
Future simple tense indicates actions expected to occur (e.g., She will walk).
Present perfect tense is used for actions that occurred at an indefinite time or have relevance to the present (e.g., She has walked).

Subjects and verbs must match in number; singular subjects pair with singular verbs, and plural subjects pair with plural verbs.
Example of agreement: She runs (singular subject and verb) vs. They run (plural subject and verb).

Modifiers should closely follow the words they describe to prevent confusion or ambiguity.
Correct placement example: "red car" (adjective + noun) versus incorrect usage like "car red."

In active voice, the subject carries out the action (e.g., The cat chased the mouse).
In passive voice, the subject receives the action (e.g., The mouse was chased by the cat).

Periods signal the end of a sentence.
Commas separate items in lists or clauses for clarity.
Semicolons connect closely related independent clauses, indicating a stronger relationship than a period.
Colons introduce lists, explanations, or quotations.
Quotation marks denote direct speech or specific quotations.

Run-on sentences occur when multiple independent clauses are incorrectly joined without proper punctuation.
Sentence fragments are incomplete sentences that lack necessary elements like a subject or verb.
Misplaced modifiers create confusion by being improperly positioned, leading to unclear or nonsensical meanings.