ACT Vocabulary:
learn the words that matter most
When I work with students to prepare for the ACT, I usually don’t recommend focusing on vocabulary flashcards. There are simply too many words in English to memorize all of them out of context this way, and that time is far better spent doing practice tests, learning ACT strategies, and simply reading.
However, there are some words that are worth learning specifically for the ACT.
These are words that are very frequently featured in ACT questions, and that can change the entire meaning of a sentence or paragraph.
Read on to see the list of words that I recommend students memorize for the ACT, and grab this free pdf to get a handy vocabulary study list.
Transition words
The most important vocabulary words to know for the ACT are transition words (or phrases).
Transition words connect two different ideas. They control how two ideas are connected. Depending on which transition word you choose, you can create wildly different logical relationships between the ideas.
Consider the different meanings of these sentences:
I like him — however, my mom likes him, too.
I like him — furthermore, my mom likes him, too.
There’s a totally different story there, right?
The ACT tends to focus on transition words a lot. Up to 10% of questions on the English section of the ACT are specifically focused on transition words, and many more questions on both the English section and the Reading section deal with transition words to a significant extent. That’s a lot of ACT test questions!
To do well on the ACT, make sure you understand and are comfortable using all of these transition words, organized by the type of relationship between ideas they create. Words in bold are words that have appeared on the ACT very often in recent years and should be prioritized:
Cause
As
As long as
Because
Because of
On account of
Since
Due to
Result & Effect
Therefore
Thus
As a result
As a consequence
Consequently
Subsequently
Correspondingly
Hence
Accordingly
So
Then
For this reason
As such
Similarity & Agreement
Likewise
Similarly
In the same vein
Equally important
Equally
Contrast
But
Yet
Still
While
However
Rather
In contrast
On the other hand
On the contrary
Contrary to this
Nonetheless
Nevertheless
Although
Even though
Then again
In reality
Whereas
Despite
Conversely
Alternately
Alternatively
Rather
Regardless
Notwithstanding
After all
At the same time
Meanwhile
Otherwise
Though
Concession
Granted
Still
Naturally
Of course
To be sure
It is true
In any case
At any rate
Intensifying & Emphasis
Most importantly
In fact
Indeed
Certainly
Moreover
As a matter of fact
Above all
Truly
To be sure
Surely
Undoubtedly
Of course
Furthermore
Definition & Clarification
In other words
That is
That is to say
To clarify
Namely
To explain
As such
Effectively
Essentially
In essence
Purpose & Condition
If
Unless
In order that
With this in mind
So that
For this purpose
For the purpose of
In the hope that
To this end
To that end
To the end that
In view of
In the event that
Granted that
Given that
Lest
Provided that
Given that
So as to
Summary
In conclusion
In sum
To sum up
In short
After all
In general
All things considered
Altogether
Overall
On the whole
In any event
At any rate
All in all
Ultimately
By and large
Time & Sequence
Before
Formerly
Earlier
Now
Soon
To begin with
Until
As soon as
As long as
Once
While
Simultaneously
Concurrently
Meanwhile
In the meantime
At length
Next
Subsequently
Following
After
After that
Afterwards
Henceforth
Then
When
Suddenly
Instantly
Immediately
Occasionally
Sometimes
Always
Eventually
In time
So far
Until now
Now that
Addition & Enumeration
Firstly (secondly, thirdly, etc)
And
Moreover
In addition
Additionally
Also
As well as
Alongside
Further
Furthermore
Besides
Even more
On the other hand
Example
For example
For instance
As an illustration
In particular
Notably
Including
Such as
In the first place
Want help understanding and learning these words? Looking for real ACT questions that feature transition words?
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Debate words
The other category of words that are particularly important for the ACT are what I like to call “debate” words or “ideas” words.
These are words that explain how ideas are related, but aren’t transition words. Instead, many of these words are verbs (action words) or nouns (things).
I’ve created this list after many years of working with students and noting which hard words on the ACT actually cost students questions vs. which words students can work around.
Often the entire meaning of a ACT question or multiple-choice answer hinges on “debate” words like these, so they’re harder to work around or guess with context. They might appear on the English section, of course, but these words are also very important to the science and social science passages on the ACT Reading section. They’re also crucial to understanding the ACT Science section.
These words are also critical to understanding the kinds of texts students will have to read in college or even later as a working adult, so learning these words will have many benefits beyond the ACT.
I’ve grouped these “debate” or “ideas” words into broad categories to make them easier to learn:
Proof
Evidence
Inference
Imply
Implicit
Explicit
Determine
Establish
Generalize
Assume
Reflect
Justify
Gauge
Account for
Validate
Verify
Confirm
Yield
Reveal
Agreement & Communication
Augment
Enhance
Convey
Emphasize
Heighten
Characterize
Indicate
Advance
Highlight
Underscore
Clarify
Endorse
Derive
Outline
Foster
Maintain
Concede
Assert
Confirm
Disagreement
Contradict
Undermine
Refute
Dispute
Counter
Lament
Challenge
Impede
Contrast
Restrict
Undercut
Dismiss
Mourn
Hinder
Change
Alternative
Modify
Mutate
Digress
Want to try real ACT questions that use these key vocab words? Sign up for one-on-one tutoring with me here or email info@ivybloomacademics.com for more advice about how to make your study time as effective as possible.
Important content words
Finally, there are a small handful of words that appear so often on the ACT as key ideas that I’ve listed them here.
Remember that in general I don’t think it’s worth it to memorize list lists of ACT vocabulary words. With very few exceptions, the only words that I think are worth it to really make sure you know are the transition words and “debate” words listed above.
However, these are words that not only have appeared many times over the years, but are often crucial to understanding the main idea of a passage or a question. Unlike many other tough vocabulary words, these are key words that are hard to skip over or figure out by context.
These words are either integral to the content of a passage, or they’re used to describe the tone of a passage.
Here’s my final list of important words to learn for the ACT:
Content
Oversight
Amass
Profit
Net cost
Net profit
Base cost
Deposit
Rational
Compel
Pragmatic
Indifferent
Virtuous
Pervasive
Justification
Scarcity
Uncertainty
Methodology
Proximity
Conclusive
Valid
Hypothesis
Generalization
Appease
Lack
Preceding
Former
Latter
Tone
Condescending
Ironic
Earnest
Naïve
Juvenile
Vivid
Scorn
Dramatize
Emphatic
Ominous
Abrupt
Sensational
Intricate
Curious about which real ACT passages on recent tests have used these words? Get access to dozens of real ACT tests, including tests from 2022 and 2023, when you work one-on-one with me for test prep. Sign up for high-quality ACT tutoring with me here or email info@ivybloomacademics.com to answer any questions.
Building a strong vocabulary
In general I don’t recommend memorizing hundreds or thousands of ACT vocabulary words out of context. This may have a small benefit for the ACT, but all that study time would be far better spent on more effective types of ACT prep.
Apart from learning the limited list of high-priority words I’ve given here, the best way to build your vocabulary for the ACT and other tests is simply to read.
I’m a big fan of following your interests and choosing whatever books you genuinely enjoy. There’s lots of good evidence that the most important factor is the sheer amount of time you spend reading, not necessarily reading the “right” books.
That said, if you really want to expand your vocabulary, try reading at least some books that use some words you don’t know. Once in a while, take the time to look up some of these words (takes just a few seconds on your phone) — but you’ll gradually learn words based on context, too, without even realizing it.
For example, I know that I’ve got a very strong vocabulary. (For context, I got perfect scores on the language sections of the ACT and the SAT on the first try, I placed in a national vocabulary competition in middle school, I won many awards for my writing as a student at Princeton, and I’ve worked as a professional editor for big-name academic presses. I’m pretty good with words!)
But whenever I read novels by the English author A. S. Byatt, who has won the Booker prize and has written some of my favorite fiction books, there are always plenty of words that are new to me in every chapter. I know that reading Byatt’s books stretches my mind and my vocabulary in a way that some of my other favorite books simply don’t.
My other recommendation to ambitious students who really want to boost their vocabulary and reading skills is to read a more diverse array of books.
Definitely keep reading the books that you enjoy most, but try reading at least two non-fiction books per year on some topic that interests you. Try reading books that are written for adults, not for teens. Try reading something written about science, and something the uses statistical reasoning. Maybe try something that’s more abstract and philosophical. I still remember attempting to read a literary criticism book about my favorite poets (Keats and Shelley) when I was in high school. Did I fully understand it? Definitely not. But grabbing this scholarly book from the library and attempting to read some of it really expanded my ideas about what academic writing could be.
If you’re not a huge fan of reading books, you can also listen to books on tape or more academic podcasts, like “In Our Time” from the BBC, which interviews leading scholars about a different subject in history, science, or literature every week.
Reading a wide range of books across both fiction and non-fiction gives you a superpower that will be a huge help not only on the ACT, but in college and throughout the rest of your life.
When I work with students one-on-one on test prep and getting ready for college, I often help students find books that will interest them and boost their skills in a fun way. To work with me or get advice about reading lists, reach out at info@ivybloomacademics.com.
Let’s summarize:
don’t waste time memorizing hundreds of ACT vocab words out of context — this study time will be far more effective focused on other types of ACT prep
do learn a limited number of key vocab words: transition words, debate words, and a few more words that show up again and again on the test
grab the free pdf below to get a list of the most important ACT vocab words and their definitions
build a strong vocabulary naturally by reading lots!
read books you enjoy, but for the most growth also include a few books on other topics (especially non-fiction books that feature analytical and statistical thinking)