Model-1
Wrong Sentence:
Raja had scarcely put the phone down than the doorbell rang.
Why?
This sentence is not properly constructed. ‘Scarcely’ should be followed by ‘when’ but not ‘than’. Moreover, when two actions in the past follow one another, one should be in past perfect and the other in simple past. This part is correct in this sentence.
Right Sentence:
Raja had scarcely put the phone down when the doorbell rang.
Model-2
Wrong Sentence:
No sooner had the mechanic repaired the TV when he delivered it to the customer.
Why?
‘No sooner......than’ is an idiomatic expression that is used to show that one thing happens immediately after another thing. Notice the correct usage of past perfect and simple past tenses.
Right Sentence:
No sooner had the mechanic repaired the TV than he delivered it to the customer.
Model-3
Wrong Sentence:
Although I reminded him several times, Madhu neither paid off my debt nor his cousin’s.
Why?
In the first part ‘neither’ is used before ‘paid ofT, a verb. In the second part ‘nor’ is used before the pronoun ‘his’. So ‘neither’ should be placed before the word ‘my’.
Right Sentence:
Although I reminded him several times, Madhu paid off neither my debt nor his cousin’s.
Model-4
Wrong Sentence:
Rahul asked them that when they had come back from the trip.
Why?
The words such as ‘where’, ‘when’, ‘how’ and ‘why’ can be used as interrogative adverbs. In such cases, ‘that’ should not be used before interrogative adverbs.
Right Sentence:
Rahul asked them when they had come back from the trip