Comparatives & Superlatives — So sánh — IELTS Grammar

Tóm tắt

Tiếng Anh có ba mức so sánh:

Mức	Tên gọi	Ý nghĩa	Ví dụ
Bình thường	Positive	như nhau	big, beautiful
So sánh hơn	Comparative	A hơn B	bigger, more beautiful
So sánh nhất	Superlative	nhất trong nhóm	the biggest, the most beautiful

Tại sao quan trọng

So sánh xuất hiện liên tục trong IELTS: - Writing Task 1: Sales were higher than the previous year / The UK had the highest rate of... - Writing Task 2: Cities are more polluted than rural areas / Education is one of the most important investments... - Speaking: This city is much bigger than my hometown / I prefer reading more than watching TV

Cấu trúc Comparative

Tính từ/Trạng từ ngắn (1 âm tiết, hoặc 2 âm tiết kết thúc -y)

Adjective + -er + than

Tính từ	Comparative	Quy tắc thêm đuôi
tall	taller	thêm -er
nice	nicer	bỏ -e, thêm -er
big	bigger	nhân đôi phụ âm cuối
happy	happier	-y → -ier
easy	easier	-y → -ier

This book is cheaper than that one.
She runs faster than him.
My new job is easier than the old one.

Tính từ/Trạng từ dài (2+ âm tiết, không kết thúc -y)

more + Adjective + than

This solution is more efficient than the previous one.
She speaks more fluently than I do.
Online shopping is more convenient than going to the store.

Bất quy tắc

Dạng gốc	Comparative	Superlative
good / well	better	the best
bad / badly	worse	the worst
far	further / farther	the furthest / farthest
little	less	the least
much / many	more	the most
old	older / elder	the oldest / eldest

She's better at maths than her brother.
Things got worse before they got better.
I have less time today than yesterday.

Cấu trúc Superlative

Tính từ ngắn

the + Adjective + -est

Tính từ	Superlative
tall	the tallest
nice	the nicest
big	the biggest
happy	the happiest

He is the tallest student in the class.
This is the cheapest option available.

Tính từ dài

the most + Adjective

This is the most interesting book I've ever read.
She's the most experienced candidate for the job.
Tokyo is one of the most populated cities in the world.

Superlative + ever: Dùng Present Perfect sau superlative: - It's the best film I've ever seen. - That was the most difficult exam she'd ever taken.

Các cấu trúc so sánh quan trọng

1. As...as (so sánh bằng)

as + Adjective/Adverb + as

She's as talented as her sister.
The exam was not as difficult as I expected.
He doesn't earn as much as she does.

Phủ định: not as...as = less...than - This hotel is not as expensive as that one. = This hotel is less expensive than that one.

2. Much / Far / A lot / Even / Slightly (nhấn mạnh mức độ so sánh)

much / far / a lot / even / slightly + comparative

The new model is much faster than the old one.
She's far more qualified than the other applicants.
Prices are slightly higher than last year.
The second exam was even harder than the first.

Không dùng "very" với comparative: - ❌ She's very taller than me. - ✅ She's much taller / far taller than me.

3. The + comparative, the + comparative

Diễn tả mối quan hệ tỉ lệ thuận:

The + comparative..., the + comparative...

The harder you work, the better your results.
The more you practise, the more confident you become.
The older he gets, the wiser he becomes.

4. Twice / Three times as...as (so sánh bội số)

twice / three times / half + as + Adjective + as

The population of China is four times as large as that of the United States.
This laptop costs twice as much as the one I bought last year.
My commute is half as long as my colleague's.

5. Less / The least (so sánh kém)

less + Adjective + than
the least + Adjective

This approach is less effective than the traditional method.
Of all the options, this one is the least expensive.

So sánh trong mô tả dữ liệu (IELTS Task 1)

Cần diễn đạt	Cấu trúc	Ví dụ
A cao hơn B	A is higher/greater than B	Sales in 2020 were higher than in 2019.
A thấp hơn B	A is lower/smaller than B	UK rates were lower than those in the US.
A cao nhất	A has the highest...	China has the highest population.
A thấp nhất	A has the lowest...	Iceland has the lowest crime rate.
Gần bằng nhau	A is almost as high as B	France's figures were almost as high as Germany's.
Gấp đôi	A is twice as high as B	The rate in 2020 was twice as high as in 2010.
Chênh lệch nhỏ	slightly / marginally higher/lower	Figures were slightly higher in urban areas.
Chênh lệch lớn	significantly / considerably higher	Costs were significantly higher in London.

Lỗi thường gặp

Lỗi 1: Dùng "more" với tính từ ngắn

❌ She is more tall than her brother.
✅ She is taller than her brother.
❌ This is more cheap than that.
✅ This is cheaper than that.

Lỗi 2: Quên "than" sau comparative

❌ My city is bigger my hometown.
✅ My city is bigger than my hometown.

Lỗi 3: Quên "the" trước superlative

❌ She is most intelligent student in class.
✅ She is the most intelligent student in class.

Lỗi 4: Dùng "very" thay "much/far" trước comparative

❌ He is very smarter than me.
✅ He is much smarter / far smarter than me.

Lỗi 5: Nhầm "good-better-best" và "well-better-best"

❌ She sings more good than him.
✅ She sings better than him.
❌ This is the most good restaurant.
✅ This is the best restaurant.

Lỗi 6: Dùng comparative thay superlative khi so sánh 3+ thứ

❌ Of the three candidates, she is more qualified.
✅ Of the three candidates, she is the most qualified.

Ứng dụng trong IELTS

Writing Task 1 — so sánh dữ liệu:

Sales in France were considerably higher than those in Germany throughout the period.
The proportion of people aged 65+ was the highest in Japan, at twice as much as in the UK.
Urban areas showed slightly higher unemployment rates compared to rural regions.
The greater the investment in education, the lower the poverty rate tended to be.

Writing Task 2 — phân tích và lập luận:

City life is often far more stressful than rural living, due to noise, traffic, and high costs.
Renewable energy is becoming increasingly competitive with fossil fuels.
Education is arguably one of the most powerful tools for reducing inequality.
People in developed countries consume significantly more resources than those in developing nations.

Speaking — mô tả và so sánh:

My hometown is much smaller than Hanoi, but I think it's far more peaceful.
I find speaking more challenging than writing, because you can't take time to think.
The more I practise English, the more confident I feel using it.

Bài tập luyện

Chia dạng đúng: comparative hoặc superlative

Paris is one of ___ (beautiful) cities in Europe.
He's ___ (tall) than his father.
The exam was ___ (difficult) than I expected.
Of all the subjects, Maths is ___ (challenging) for me.
She works ___ (hard) than anyone else in the office.

Sửa lỗi

She is more old than her colleague.
This coffee is the more expensive in the menu.
He runs very faster than me.
Of the two options, the first is most practical.
London is bigger as Paris.

Đáp án

Chia dạng: 1. the most beautiful | 2. taller | 3. more difficult | 4. the most challenging | 5. harder

Sửa lỗi: 1. She is older than her colleague. (old → older, không dùng "more") 2. This coffee is the most expensive on the menu. (the + most + long adj; "in the menu" → "on the menu") 3. He runs much faster than me. (dùng much/far, không dùng very) 4. Of the two options, the first is more practical. (hai đối tượng → comparative, không superlative) 5. London is bigger than Paris. (dùng "than", không "as")

Tóm tắt nhanh

Tính từ ngắn (1-2 âm tiết): -er / the -est - Thêm -er/-est: tall → taller → the tallest - Nhân đôi phụ âm: big → bigger → the biggest - -y → -ier/-iest: happy → happier → the happiest

Tính từ dài (3+ âm tiết): more / the most - more beautiful / the most beautiful

Bất quy tắc: good→better→best | bad→worse→worst | much/many→more→most | little→less→least

Cấu trúc quan trọng: - so sánh bằng: as...as - nhấn mạnh: much / far / considerably / significantly + comparative - tỉ lệ: the + comparative, the + comparative - bội số: twice / three times as...as

Không dùng "very" trước comparative — dùng "much/far/a lot/even" thay thế!

Lỗi phổ biến — "more better" và bỏ "than"

Lỗi 1: Stack "more" + comparative form

Tiếng Việt "hơn" có thể đi với mọi tính từ. Người học VN bê "more" + đã-comparative-rồi → double comparative.

❌ "She is more better than him." → ✅ "She is better than him." ❌ "Hanoi is more bigger than Da Nang." → ✅ "Hanoi is bigger than Da Nang." ❌ "This problem is more more difficult." → ✅ "This problem is more difficult."

Quy tắc: Adjective ngắn (1 syllable, hoặc 2 syllables ending in -y) → -er. Adjective dài → more + adj. KHÔNG đi cùng nhau.

Lỗi 2: Bỏ "than"

Tiếng Việt có thể so sánh bằng juxtaposition: "tôi cao bạn" (= cao hơn). English bắt buộc "than".

❌ "She is taller me." → ✅ "She is taller than me." ❌ "Hanoi is older Saigon." → ✅ "Hanoi is older than Saigon."

Mẹo: Mọi comparative cần có ít nhất một trong: "than X" (so với X) hoặc context rõ ràng (e.g., "Which is bigger?" — câu trả lời ellipsis chấp nhận).

Comparatives & Superlatives — So sánh