Fill in the blank with most appropriate option:
No sooner had we reached the station ___ the train left.
Show answer & explanation
Correct answer: A
Explanation
Correct Answer
than
Explanation
The question asks you to select the correct conjunction to complete a correlative pair in the sentence.
In English grammar, certain words are paired together by strict rule as correlative conjunctions to indicate that one action happened immediately after another. The adverbial phrase "No sooner" is a comparative form because it contains the word "sooner" (the comparative degree of soon). Because it is a comparative form, it must always be paired with the conjunction than.
Let's evaluate why the other options are incorrect:
When is a common trap because it is used with different introductory phrases like "Hardly," "Scarcely," or "Barely" (such as "Hardly had we reached the station when the train left"). It cannot be paired with "No sooner."
Then is a time-marking adverb, not a conjunction. While it sounds phonetically identical to "than" in spoken English, using "then" here is a major grammatical error.
That is a relative pronoun or a general subordinating conjunction, which cannot complete this specific correlative structure.
Because the formulaic pair is always "No sooner... than", Option 1 is the only grammatically acceptable choice.
Key Points
To easily score marks on these specific conjunction questions during competitive exams, memorize the fixed pairs exactly as they are written:
No sooner is always followed by than
Hardly, Scarcely, or Barely are always followed by when
Additionally, notice the structure "had we reached" instead of "we had reached." When these negative phrases start a sentence, they trigger an inversion where the helping verb comes before the subject.