When something is compared to itself, usual is fine.
When something is compared to a subgroup to which it belongs, is usual should be used.
For example:
1. He is nicer than usual
2. He is faster than is usual for any human being.
3. Ram is faster than usual today.
4. Emails are often written in a much formal way than is usual in writing.
5. The sun looks less brightly than usual to-day.
6. The new sports car is heavier than is usual for a performance automobile, but it is exceptional because of its high-powered engine .
7. Successful completion of Grammar course is not easy and requires more planning and preparation than is usual for normal course completion .
8. There was a higher ratio of comedy to drama than is usual in a one hour show.
9. I checked this article more carefully than usual for grammatical errors.
10. The gravel was damper than usual, since it rained heavily yesterday.
11. Today I was busier than usual at work.
(A) usual
(B) is usual
(C) has been usual
(D) one usually is
(E) it is usual
Answer: B
When something is compared to a subgroup to which it belongs, is usual should be used.
For example:
1. He is nicer than usual
2. He is faster than is usual for any human being.
3. Ram is faster than usual today.
4. Emails are often written in a much formal way than is usual in writing.
5. The sun looks less brightly than usual to-day.
6. The new sports car is heavier than is usual for a performance automobile, but it is exceptional because of its high-powered engine .
7. Successful completion of Grammar course is not easy and requires more planning and preparation than is usual for normal course completion .
8. There was a higher ratio of comedy to drama than is usual in a one hour show.
9. I checked this article more carefully than usual for grammatical errors.
10. The gravel was damper than usual, since it rained heavily yesterday.
11. Today I was busier than usual at work.
GMAT Question example:
(A) usual
(B) is usual
(C) has been usual
(D) one usually is
(E) it is usual
Answer: B
