Here we have a comma splice: the first two independent clauses in this sentence are incorrectly separated by a comma. (The latter two of the three independent clauses are correctly punctuated with a comma and a conjunction word.) Multiple independent clauses in the same sentence must be punctuated by either a comma with a conjunction or a semicolon. Accurately punctuated, the sentence should appear as follows: “The inhabitants of Ulan Bator inhabit a unique cultural juxtaposition; they are in a cosmopolitan city with a population of more than 1 million residents, but they are also influenced by a nomadic heritage.” 

Here we have a comma splice: two independent clauses that are incorrectly separated by a comma. Two independent clauses in the same sentence must be punctuated by either a comma with a conjunction or a semicolon. Correctly punctuated, this sentence would read: “Contrary to popular belief, the artisanal cheese-makers did not live a decadent, gourmet lifestyle; they had to scrimp and save on their personal grocery expenditures in order to keep their business afloat.” Elsewhere, commas are correctly separating two adjectives in a list and an independent clause from a dependent clause.

Here we have a comma splice: two independent clauses that are incorrectly separated by a comma and should instead be punctuated by either a comma with a conjunction or a semicolon. Written correctly, this sentence would read: “Lee has always been a proponent of tighter gun regulations; he believes countries that enforce strict firearms laws are generally more peaceful, safe, and open-minded than those that don’t.” At the end of the sentence, commas are appearing correctly to punctuate the list.

Here we have a comma splice: two independent clauses that are incorrectly separated by a comma and should instead be punctuated by either a comma with a conjunction or a semicolon. Written correctly, this sentence would read: “A rigorous national curriculum should encompass not only excellent preparation in reading and mathematics but also so-called extracurricular activities such as sports, arts, and music; studies have shown that the most successful people in life are often those with divergent, varied interests.” “The list “sports, arts, and music” is correctly punctuated with commas, as are the two adjectives that precede “interests.”

Here we have a comma splice: two independent clauses that are incorrectly separated by a comma and should instead be punctuated by either a comma with a conjunction or a semicolon. Written correctly, this sentence would read: “Prison reform is one issue the senator is expected to address in his upcoming bill; the bill would include long-awaited laws to preserve inmates’ basic human rights.” The apostrophe is correctly forming a plural possessive.

This is another comma splice. In other words, we have two independent clauses that are incorrectly separated by a comma and should instead be punctuated by either a comma with a conjunction or a semicolon. The first and last commas in this sentence are both correct, since they separate dependent clauses from the main independent clause. The correct sentence is “Ever since he learned how to speak, my little brother has been asking for a dog, my parents think he should wait until he’s old enough to take care of a pet, though.”

Here is another comma splice. We have two independent clauses (“With drought threatening crops, livestock, and landscaping across the state, California had no choice but to enact water restrictions” and “residents complained, but most understood the necessity of the measures”) that are incorrectly separated by a comma and should instead be punctuated by either a comma with a conjunction or a semicolon. The list is correctly punctuated with commas.

This is another comma splice. In other words, we have two independent clauses that are incorrectly separated by a comma and should instead be punctuated by either a comma with a conjunction or a semicolon. The first and last commas in this sentence are both correct: The first one separates the dependent from the independent clause, and the last one separates two adjectives that are modifying the same noun. they separate dependent clauses from the main independent clause. The correctly punctuated sentence is “As most people learn in elementary school, butterflies undergo astounding metamorphoses in their short lifetimes; they begin as larvae and quickly transform into pupae and then beautiful, multicolored adults.”

A comma correctly separates a dependent clause (“Contrary to popular belief”) from an independent clause (“chicken soup does not prevent one from contracting the common cold”), but it incorrectly separates two independent clauses (“chicken soup does not prevent one from contracting the common cold” and “it simply strengthens the immune system by providing nutrition”). This is called a comma splice, and it can be fixed by replacing the comma with a semicolon.

Here we have a comma splice: two independent clauses that are incorrectly separated by a comma. Two independent clauses in the same sentence must be punctuated by either a comma with a conjunction or a semicolon. Correctly punctuated, this sentence would read: “My manager says it’s always better to apologize than to argue with our customers; they’re not always right, but it’s our job to pretend they are.”