The Semicolon
12 rules
Semicolon Between Independent Clauses (No Conjunction)
Use a semicolon to join two independent clauses that are closely related in meaning when no coordinating conjunction (and, but, or, nor) connects them. Each clause could stand alone as its own sentence, but the semicolon signals their close relationship. If a coordinating conjunction is present, use a comma instead (not a semicolon).
Semicolon Before Conjunctive Adverbs and Transitional Expressions
In a compound sentence, use a semicolon before the second independent clause when it begins with a conjunctive adverb or transitional expression such as however, therefore, consequently, furthermore, moreover, nevertheless, indeed, in fact, namely, on the contrary, or similarly. Follow the transitional word with a comma. Exception: the words hence, so, thus, and yet are no longer set off by a following comma. Important: if the transitional expression merely interrupts one clause (rather than introducing a second independent clause), set it off with commas instead — no semicolon.
Semicolon Before Explanatory Words Introducing a List
Use a semicolon before words that introduce an explanation, enumeration, or list — such as namely, that is, that is to say, for example, e.g., i.e., as, or to wit. A comma follows the explanatory word. The material after the explanatory expression does not need to be an independent clause. However, if the explanation after the introductory word is only a single word or very short phrase (not a list), use commas around the explanatory expression instead of a semicolon.
Semicolon in a Series When Items Contain Commas
Use semicolons (instead of commas) to separate items in a series when the individual items already contain commas. This prevents confusion about where one item ends and the next begins. Common situations include lists of cities with states, dates with amounts, people with identifying descriptions, and multiple objections with their grounds.
Semicolon Between Long Dependent 'That' Clauses in a Series
When a sentence contains a series of dependent clauses each introduced by 'that,' use semicolons to separate them if the clauses are long (roughly ten-plus words each). If the 'that' clauses are short, commas are sufficient. If there are only two 'that' clauses joined by a conjunction (and, but, or, nor), no punctuation is needed between them. If there are only two 'that' clauses with no conjunction, use a comma if they are short and simple, or a semicolon if they are long or contain internal commas. When the clauses are numerous or tabulated, semicolons help maintain clarity even if individual clauses are short.
Semicolon Before Conjunction When Clauses Are Long with Internal Commas
Use a semicolon (rather than just a comma) before a coordinating conjunction (and, but, or, nor) joining two independent clauses when either clause is very long and already contains commas. The semicolon provides a stronger visual break, preventing the conjunction's comma from getting lost among the internal commas.
Semicolon in Numbered or Lettered Enumerations
Use a semicolon after each item in a numbered or lettered series when the items are long phrases or clauses. Enumerations can be introduced by numbers (1), (2), (3) or letters (a), (b), (c), or written out as words (first, second, third). If the enumerated items are short and contain no internal commas, commas may be used instead of semicolons. When enumerations are written as words, place a comma after the word and a semicolon between items.
Semicolon When the Verb Is Omitted in the Second Clause
Use a semicolon to separate two independent clauses when the verb in the second clause is omitted because it is understood from context. A comma takes the place of the missing verb within the second clause. This construction is common in parallel or comparative statements.
Semicolon Between Very Long Independent Clauses Joined by a Conjunction
A semicolon may be used to separate two very long independent clauses joined by a coordinating conjunction (and, but, or, nor), even when the clauses don't have internal commas, simply because of their length. The semicolon provides a stronger pause for the reader. Alternatively, the sentence may be split into two separate sentences beginning with the conjunction.
Semicolon Always Goes Outside Quotation Marks
When a semicolon and a closing quotation mark appear at the same point in a sentence, the semicolon always goes outside (after) the closing quotation mark. This is the opposite of the period rule — unlike periods, semicolons are never placed inside quotation marks.
No Capitalization After a Semicolon
Do not capitalize the word after a semicolon unless it is a word that is always capitalized (such as a proper noun or 'I'). Leave just one space after a semicolon. The semicolon connects related clauses within a single sentence — it does not start a new sentence, so no capital letter is needed.
Comma (or No Comma) After Conjunctive Adverbs Based on Syllable Count and Context
After a conjunctive adverb with two or more syllables (however, therefore, consequently), use a comma. After a conjunctive adverb with only one syllable (yet, still, thus, so, then), use no punctuation. When a coordinate conjunction (and, but, or, nor) precedes a word that could be a conjunctive adverb, use the punctuation appropriate for the coordinate conjunction, not the conjunctive adverb punctuation. If a word that can be a conjunctive adverb is in position at the front but does not have an independent subject and verb after it, use a comma in front of it — not a period or semicolon — because it is functioning as an adverb, not a conjunction. When there is a coordinate conjunction followed by a conjunctive adverb-type word and there is NOT an independent subject and verb after it, do not use a comma before the coordinate conjunction. When there is no coordinate conjunction but there is a conjunctive adverb-type word and there is NOT an independent subject and verb after it, use a comma to replace the missing conjunction.