Grammar · Free lesson
As … as: compare equal qualities
Two backpacks each weigh two pounds. Neither is heavier. You need a comparison that expresses equality.
Professor Scott MendozaThe short answer
Use as + plain adjective + as for equal degree: as quiet as. Use not as … as when the first thing has less of that quality: not as heavy means lighter.
Keep the adjective in its plain form.
Say “This bag is as heavy as that one,” not “as heavier as.” The two as words frame heavy. In the negative, keep that same frame and add not after is.
Compare the examples
The red bag is as heavy as the blue bag.
The red bag is not as heavy as the blue bag.
This ticket is as expensive as that ticket.
Not as expensive means cheaper by comparison. It does not automatically mean cheap.
Build the meaning step by step
Choose the quality
quiet
Frame it with as
The library is as quiet as the study room.
Try it now
Read the comparison
Read all answers and explanations
Both rooms have the same width. Choose the equality comparison.
This room is as wide as that room.As wide as uses the plain adjective and expresses equal width. Wider than says the widths differ.
“A is not as expensive as B.” Which interpretation follows?
A costs less than B.A has a lower price than B. Neither price has to be low in absolute terms.
“The small box is not as light as the large box.” Which box is heavier?
The small box.Not as light means heavier. Do not let the physical size distract you from the stated weight comparison.
Put it into practice
Repair the equality sentence
Both routes take the same time. Keep that equality and fix the pattern.
Route A is as faster than route B.
See a model answer
Route A is as fast as route B.
Repair both parts: remove the comparative ending and replace than with as.
A little more clarity
Common questions
A few useful details before you move on.
Does as … as mean the things are identical?
No. It compares the named quality. Two bags can be equally heavy while having different colors or sizes.
The black bag is as heavy as the green bag.
Can I end this pattern with than?
Use as to complete an equality comparison. Than belongs with a comparative such as heavier, which expresses a difference.
as heavy as / heavier than
Take it into your day
Equal degree: as + adjective + as. Lower degree: not as + adjective + as.
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