1. He is less tall than Tom.

Question

2. Tom is taller than he.

3. He is less smart than Tom.
4. Tom is smarter than he.

5. He is less big than Tom.
6. Tom is bigger than he.

7. He is less careful than Tom.
8. Tom is more careful than he.

9. He is no thoughtful than Tom.
10. Tom is more thoughtful than he.
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Are they all grammatical?
Is each pair the same in meaning?

Answer 1

The expressions with "less" don't fit in 1, 3, and 5. Here's how I'd revise those:

1. He is shorter than Tom.
2 is fine.

3. He is not as smart as Tom.
4. is fine.

5. He is smaller than Tom.
6. is fine.

7 and 8 are fine.

9 -- I'm not sure. Do you mean this?
He is not as thoughtful as Tom.
10 is correct.