In each of the following questions, choose the option that best completes the gap(s).
No sooner had Tobi left the house _____ it began to rain.
Answer Details
The construction "no sooner...than" is a fixed correlative conjunction in English. It expresses that one event happened immediately before another. The correct sentence is: "No sooner had Tobi left the house than it began to rain."
The word "than" is the only grammatically correct partner for "no sooner." This structure uses subject-verb inversion ("had Tobi left" instead of "Tobi had left") to create emphasis, and "than" introduces the second event that followed almost instantly.
Common errors include using "when" (which pairs with "hardly" or "scarcely," not "no sooner"), "that" (which has no role in this construction), or "since" (which introduces a reason or time origin, not an immediate sequence). For examinations, remember: no sooner...than, hardly/scarcely...when.