Blog about English
Frequent learner mistakes involving punctuation and capitalization.
Punctuation and capitalization should reflect sentence structure, grammatical relationships, emphasis, and established writing conventions.
The most frequent errors involve missing sentence-ending punctuation, incorrect commas, apostrophe misuse, inconsistent quotation marks, and inappropriate capitalization.
Ordinary common nouns should not normally be capitalized unless they begin a sentence, form part of a proper name, or follow a specific capitalization convention.
For example, English is capitalized as a language name, but grammar is normally lowercase.
Names of languages, nationalities, and related national adjectives are capitalized in English.
For example, English, Ukrainian, French, and Japanese.
Season names are normally lowercase when used as ordinary common nouns.
For example, in spring, during summer, and next winter.
Job titles are generally lowercase when used descriptively but may be capitalized when functioning as formal titles before names or in organizational styles.
For example, the president versus President Lincoln.
The pronoun I is always capitalized.
For example, John and I went home.
The first word of a new sentence normally begins with a capital letter.
For example, The meeting ended. Everyone left.
Complete declarative sentences normally require a full stop or another appropriate final punctuation mark.
For example, The meeting has ended.
An indirect question embedded in a declarative sentence normally takes the punctuation of the main sentence, not automatically a question mark.
For example, I do not know where she is. but Where is she?
Exclamation marks should generally be reserved for genuine emphasis, strong emotion, surprise, or forceful commands.
Frequent use in formal writing can make prose seem overly emotional or informal.
A comma alone should not normally join two independent clauses.
For example, I called him, he did not answer is a comma splice.
A comma should not normally separate a grammatical subject from its finite verb.
For example, The main problem is time, not The main problem, is time.
A comma should not normally separate a verb from its essential object or complement.
For example, She bought a new car, not She bought, a new car.
A person or group directly addressed should normally be separated from the rest of the sentence by a comma.
For example, John, could you help me?
An introductory subordinate clause is commonly followed by a comma.
For example, If you need help, call me.
A comma is not normally required when a short subordinate clause follows the main clause.
For example, Call me if you need help is normally written without a comma.
Defining relative clauses normally do not use commas, while non-defining relative clauses normally do.
For example, The students who passed can leave versus My brother, who lives in London, is visiting.
Apostrophes should not normally be used simply to make a noun plural.
For example, books, CDs, URLs, and 1990s, not book's, CD's, URL's, or 1990's.
Its is possessive, while it's is a contraction of it is or it has.
For example, The company changed its policy versus It's raining.
Your is possessive, while you're is a contraction of you are.
For example, your phone versus you're late.
Their is possessive, they're is a contraction of they are, and there has locative or existential functions.
For example, They're meeting their friends over there.
Whose expresses possession, while who's is a contraction of who is or who has.
For example, Whose book is this? versus Who's coming?
Quotation marks should not normally surround material that is being paraphrased rather than quoted exactly.
For example, The author argues that the method is unreliable does not require quotation marks around the paraphrase.
A document should generally follow one consistent quotation-mark convention unless a deliberate nested quotation requires a different level.
For example, do not switch randomly between single and double quotation marks.
Question and exclamation marks should be placed according to whether they belong to the quoted material or the surrounding sentence.
For example, She asked, "Why are you here?" versus Did she really say "Stop"?
Compound modifiers before nouns should be hyphenated when needed to show that the words function together as one modifier.
For example, a well-known writer and a five-year-old child.
Measurement units inside number-unit compound modifiers are normally singular.
For example, a five-year-old child and a ten-kilometre race, not five-years-old or ten-kilometres.
Hyphens join words or parts of compounds, while en dashes commonly express ranges or relationships.
For example, part-time versus 2010–2020.
A hyphen is part of a word or compound, while an em dash marks a strong break, interruption, or parenthetical emphasis.
For example, well-known versus The answer—despite its simplicity—was wrong.
A colon should normally follow a complete clause when introducing a list, explanation, example, or elaboration.
For example, We need three things: time, money, and staff. Avoid The things we need are: time, money, and staff.
A semicolon should normally connect independent clauses or separate complex list items.
For example, Because it rained; we stayed home is incorrect.
Ellipses should have a clear function and should not replace ordinary punctuation throughout formal prose.
Excessive use can make writing appear hesitant, fragmented, or informal.
Repeated question marks and exclamation marks are generally informal and should be avoided in formal writing.
For example, What??? and Amazing!!! may occur in messaging but are normally inappropriate in formal prose.
Titles and headings should follow a consistent capitalization style such as sentence case or title case.
For example, How to use commas versus How to Use Commas.
Correct punctuation and capitalization require control of sentence boundaries, commas, apostrophes, quotation marks, hyphens, dashes, colons, semicolons, ellipses, and proper-name capitalization.
Before adding punctuation or capitals, identify the grammatical structure and determine whether the relevant element is a proper name, quotation, compound, clause boundary, list, or supplementary expression.