No sooner had Tobi left the house … it began to rain.

Analyze the question The sentence is "No sooner had Tobi left the house _ it began to rain." It tests a fixed grammatical pattern, the correlative construction with "no sooner".

Explain the concept "No sooner" is always paired with than, never with "when", "that" or "since".

• No sooner + past perfect (inverted) + than + past simple
• Example: No sooner had she sat down than the phone rang.

This is different from "hardly" and "scarcely", which pair with when:

• Hardly had he arrived when the meeting started.

Step-by-step solution

1. The sentence begins with "No sooner had Tobi left...", which is the inverted past perfect that follows "no sooner".
2. "No sooner" is a comparative form (like "sooner than"), so it needs than to complete the comparison.
3. Check the options: • A. since: wrong, it refers to time from a point in the past. • B. that: wrong, it does not fit this pattern. • C. than: correct. • D. when: wrong here. It is used with "hardly" and "scarcely", not "no sooner".
4. Completed sentence: No sooner had Tobi left the house than it began to rain.

Answer: C. than

Exam tip Remember "No sooner... THAN" because both words are comparative, like "sooner" and "than". For "Hardly/Scarcely... WHEN", think "hard when". JAMB tests this pair often.