1. Her new house is smaller than her old house. (So sánh hơn: S + be + adj + er + than)

2. Peter is the tallest student in my class. (So sánh nhất: S + be + the +adj +est)

3. The white dress is cheaper than the black one. (So sánh hơn: S + be + adj + er + than)

4. According to me, Maths is more difficult than English. (So sánh hơn: S + be + more + adj + than)

5. Mary is the most intelligent student in my group. (So sánh nhất: S + be + the + most + adj)

6. The Nile is the longest river in the world. (So sánh nhất: S + be + the +adj +est)

7. No mountain in the world is higher than Mount Everest. (No + N1 + be + adj + er + than + N2)

=>
1. Her new house is not as big as her old house.
2. Peter is the tallest (student) in my class.
3. The white dress is not as expensive as the black dress.
4. According to me, Maths is not as easy as English.
5. Mary is the most intelligent (person) in my group.
6. The Nile is the longest river in the world.
7. No mountain in the world is higher than Mount Everest.
So sánh nhất : 
Tính từ ngắn : the adj-est
Tính từ dài : the most adj
So sánh hơn :
Tính từ ngắn : adj-er than
Tính từ dài : more adj than
So sánh bằng : as adj as