Punctuation within a sentence

The town rebuilt the old______ stone bridge exactly as it had stood for two centuries.

Which choice completes the text so that it conforms to the conventions of Standard English?

• A) old,
• B) old:
• C) old ✓
• D) old;

Why: "Stone" names the kind of bridge and forms a unit with it, and "old" then describes that whole unit, so these are cumulative adjectives: you cannot say "stone and old bridge" or reverse them, and no mark belongs between them, which makes old correct. Writing old, inserts the comma that only coordinate adjectives take. Writing old; would require an independent clause on each side of the semicolon. Writing old: would require a complete clause before the colon and an explanation or list after it, and a noun phrase supplies neither.

The overnight survey, conducted along a stretch of river that had not been formally studied in over a decade, recorded otters, herons nesting in numbers nobody on the team had predicted______ and one very startled beaver that nearly capsized the canoe.

Which choice completes the text so that it conforms to the conventions of Standard English?

• A) predicted:
• B) predicted, ✓
• C) predicted
• D) predicted;

Why: The survey recorded three things, "otters," "herons nesting in numbers nobody on the team had predicted," and "one very startled beaver," so the comma before the final "and" is required and predicted, is correct. A semicolon in predicted; would be right only if the items carried commas inside them, and none of these do. A colon in predicted: cannot appear mid-list, since a colon introduces a list only after a complete independent clause. Leaving it as predicted fuses the long second item to the third with no separator.

Racing to catch the last ferry of the ______ the two of us left our bags behind on the dock.

• A) night which was unusually cold
• B) night—which was unusually cold
• C) night, which was unusually cold
• D) night, which was unusually cold, ✓

Why: The clause describing the night is nonrestrictive, so it needs a comma on each side, and the closing comma also marks the end of the whole introductory phrase before the subject "the two of us," which is what night, which was unusually cold, gives you. Writing night, which was unusually cold opens the interrupter with a comma but never closes it, so the modifier runs into the main clause. Writing night which was unusually cold drops both commas, turning supplementary information into a restrictive clause and leaving no boundary before the subject. Writing night—which was unusually cold opens with a dash, so the two ends of the interrupter do not match and the introductory phrase is still left unclosed.