1. D: No error. There is a comma after the initial modifying prepositional phrase and after the first and second modifying prepositional phrases in the series of three. No comma belongs between an adjective and the noun it modifies (A), or between an auxiliary verb and verb (B). Omitting the second comma setting off the first modifying prepositional phrase (C) is wrong.
2. D: No error. A comma belongs between two consecutive adjectives modifying the same noun. A comma between verb and object (A) is incorrect. So is one between an adjective and the noun it modifies (B). Omitting a comma between two consecutive adjective (C) is incorrect.
3. A: The comma after "Nathan" is correct, but there should also be another comma before it. When an address to someone by name is inserted mid-sentence-here between subject and object-it should be set off by commas on both sides. There should not be a comma between auxiliary verb and verb (B). Having no commas to set off the inserted name (C) is incorrect.
4. B: There should be a comma between the street address and the city when stating a full address in sentence form (as well as between the city and state, as there is here). There should not be a comma between the verb and prepositional phrase (A), or between street number and street name (C).
5. C: A modifying phrase between subject and predicate should be set off by commas on both sides. Putting a comma between adverb and verb (A) or between object and preposition (B) is incorrect.
6. D: No error. The phrase modifying the subject is set off by commas both before, and after it. Removing the second comma (A) is incorrect. A comma between a noun and its modifying prepositional phrase [(B), (C)] is incorrect.
7. C: There should always be a comma between a village and country, city and state, state and country, or country and continent. There should not be a comma between the noun and modifying preposition (A), or between the subject and verb (B).
8. C: When a date is used in a modifying prepositional phrase before the subject and verb, it should have a comma after it (before subject-verb). There should not be a comma between a noun and modifying preposition (A) or between an article and the noun it modifies (B).
9. A: A comma should follow an interjection like "Oh" at the beginning of a sentence. (In some sentences, other punctuation like an exclamation point is acceptable.) A comma between subject and verb (B) is incorrect. A comma in the middle of an infinitive (C) is incorrect.
10. C: When a non-quotation clause/phrase is inserted in the middle of a quotation, it should be set off by commas on both sides. There should not be a comma between a noun and its modifying prepositional phrase (A), or between an adjective and the noun phrase it modifies (B).
