Question 173·Medium·Boundaries
Many historians believe that the diary is the most intimate form of historical _____ provides a window into the writer's private thoughts rather than public pronouncements.
Which choice completes the text so that it conforms to the conventions of Standard English?
For punctuation and boundaries questions, first test whether the words before and after the underlined portion form complete clauses (each with a subject and a verb). If both sides are complete, eliminate answers that give only a comma or no punctuation, since those usually create comma splices or run‑ons. Then decide how the second clause relates to the first: if it explains or illustrates the first clause, lean toward a colon; if it simply adds a closely related but separate statement, a semicolon may be appropriate. Always reread the full sentence with your chosen option to confirm it sounds grammatically correct and logically clear.
Hints
Look at what comes before and after the blank
Cover the answer choices and read up to the blank, then from just after the blank to the period. Ask yourself: are both parts complete sentences with their own subject and verb?
Think about the relationship between the two parts
Does the second part contrast with the first, add another separate idea, or explain why the first part is true? Identify that relationship clearly in your mind.
Match the relationship to the punctuation rule
Once you know the relationship (for example, explanation vs. contrast vs. separate idea), recall which punctuation mark is typically used after a complete sentence to introduce that kind of information.
Eliminate options that break sentence-boundary rules
Cross out any choice that would leave you with two complete sentences joined only by a comma or by no punctuation at all; those are not allowed in standard written English.
Step-by-step Explanation
Understand the meaning of the sentence
Read the full sentence and think about its meaning:
"Many historians believe that the diary is the most intimate form of historical evidence ______ it provides a window into the writer’s private thoughts rather than public pronouncements."
The sentence first makes a claim (diaries are the most intimate evidence), and then gives a reason or explanation (because they show private thoughts).
Check if each side of the blank is a complete clause
Look at the words before the blank:
- "Many historians believe that the diary is the most intimate form of historical evidence" has a subject ("many historians") and a verb ("believe"), and the rest completes their thought. This is a complete sentence.
Now look at the words after the blank:
- "it provides a window into the writer’s private thoughts rather than public pronouncements" also has a subject ("it") and a verb ("provides"). This is another complete sentence.
So you are joining two complete clauses, and the second one explains the first.
Recall the punctuation rules for joining clauses
When you join two complete clauses, you have a few options, but they must follow strict rules:
- A comma alone between two complete clauses is almost always wrong (comma splice).
- No punctuation between two complete clauses creates a run‑on sentence.
- A semicolon joins two closely related complete clauses but does not specifically signal that the second explains the first.
- A colon is used after a complete clause to introduce an explanation, example, or result.
Here, the second clause clearly explains why the diary is intimate evidence.
Match the correct punctuation to the sentence
Now test each answer choice against the rules:
- With a comma or no punctuation, you would incorrectly join two complete clauses (comma splice or run‑on).
- With a semicolon, you would show a general connection, but not the clear “here is the explanation” relationship that the sentence needs.
- The only choice that correctly places a punctuation mark after a complete clause and clearly introduces an explanation is "evidence: it".
So the correct answer is "evidence: it".