Top 200 Vocabulary Word List for the ACT | Must Know Words for Common Examination Instructions

The 200-word examination instruction list

ACT test instructions can ask whether a sentence meets an editorial goal, which passage detail supports a conclusion, or what a mathematical model represents. This guide also explains the enhanced format for U.S. and international candidates and how the optional sections fit.

The list includes instructions, short phrases and supporting vocabulary that helps you read a prompt. Use the official directions for the specific question, paper or administration.

Exam requirements · Worked examples · Fencing Method

Enhanced ACT, English and Reading directions

No.	Instruction or term	What it asks you to do
1	Enhanced ACT	Use the current format for the administration in which you will test.
2	Core Composite	Read the Composite as based on English, Math and Reading in the current format.
3	Optional Science	Check how the Science section applies to your registration and intended use of scores.
4	Optional Writing	Check whether you will take the separate essay section.
5	International administration	Use ACT’s current non-U.S. instructions and registration details.
6	Production of Writing	Judge whether wording serves the passage’s purpose, focus and organisation.
7	Knowledge of Language	Choose wording that fits meaning, precision, style and tone.
8	Conventions of Standard English	Apply rules of grammar, usage and punctuation in the sentence and passage.
9	NO CHANGE	Keep the original wording if it is the best choice in the item.
10	Delete the underlined portion	Remove the marked material if doing so best fulfils the question’s objective.
11	Placement	Choose the position that makes the sentence or paragraph work in context.
12	Add this sentence	Decide whether the proposed sentence helps and use the reason that fits the passage.
13	Best accomplishes the goal	Select the edit that serves the stated writing purpose.
14	Given that all choices are true	Use the stated writing goal to judge which accurate detail belongs.
15	Logical transition	Connect the ideas in the way required by their actual relationship.
16	Key Ideas and Details	Find central ideas, relevant details or relationships supported by a passage.
17	Craft and Structure	Read for word choice, organisation, purpose and perspective in the text.
18	Integration of Knowledge and Ideas	Connect claims and evidence across the materials the question provides.
19	Paired passages	Track which writer makes each claim before choosing a comparison.
20	Main function	Identify the purpose of the named sentence, paragraph or feature.

Reading, Math, Science and Writing instructions

No.	Instruction or term	What it asks you to do
21	According to the passage	Base the answer on what the passage supplies.
22	Preparing for Higher Math	Use the required mathematics concepts and representations to solve the item.
23	Integrating Essential Skills	Combine foundational skills when the problem requires more than one.
24	Modeling	Represent the situation with an equation, graph or other suitable structure.
25	Least possible value	Find the smallest value that meets all the stated conditions.
26	Nearest tenth	Round the result to one digit after the decimal point.
27	Greatest integer	Find the largest whole-number value that meets the condition.
28	Equivalent equation	Choose an equation with the same set of solutions.
29	Percent of the total	Divide the relevant part by the whole and convert to a percentage.
30	Represent the situation	Match the verbal relationships to a mathematical form.
31	Interpretation of Data	Use the values, scales and relationships in the supplied displays.
32	Scientific Investigation	Read the method, variables and comparison conditions before drawing conclusions.
33	Evaluation of Models	Judge how well the named model or explanation fits the evidence.
34	Conflicting Viewpoints	Keep competing explanations separate and identify their points of disagreement.
35	Data Representation	Read the presented graphs, tables and other displays for the relevant comparison.
36	Research Summaries	Use the described studies, procedures and results to answer the question.
37	Perspective in Writing	Explain your own position and how it relates to another perspective as directed.
38	Evaluate a perspective	Explain the strengths, limits or assumptions of a stated position.
39	Essay task	Read the instructions for your argument, its development and its relation to the perspectives.
40	STEM score	Check ACT’s reporting guidance if you take the Science section.

Question wording, data and answer choices

No.	Instruction or term	What it asks you to do
41	Most logical placement	Choose where a sentence best fits the progression of ideas.
42	Most precisely	Choose the wording whose meaning fits the context most closely.
43	Main purpose	Identify what the text as a whole is trying to accomplish.
44	Central idea	Choose the option that captures the main point at the right scope.
45	Best describes	Choose the description that most accurately fits the stated target.
46	Best illustrates	Choose the example or quotation that most directly shows the idea.
47	Most directly supports	Pick the evidence with the clearest connection to the named claim.
48	Would weaken	Find the hypothetical finding that would reduce support for the claim.
49	If true	Assume the answer choice is true while judging its effect on the claim.
50	Function of the underlined portion	Explain what the marked part does within the larger text.
51	Overall structure	Track how the text’s main parts are organised.
52	Words in context	Choose the sense or expression that fits the local wording and purpose.
53	Compare the passages	Identify a similarity or difference supported by both passages.
54	Text 1	Keep the first text’s position separate when comparing sources.
55	Text 2	Identify the second text’s response to the precise claim being compared.
56	Author’s claim	Find what the named author argues or asserts.
57	Point of agreement	Find what both sources would endorse based on the evidence.
58	Introduce	Choose wording that supplies the context needed for the stated audience.
59	Emphasise	Choose wording that gives the requested idea or contrast prominence.
60	Generalise	State a broader point only to the extent that the examples support it.
61	Transitions	Identify the relationship between ideas before choosing a connecting expression.
62	Continuation	Choose a link that adds a point in the same direction.
63	Concession	Acknowledge a point before shifting to the principal claim.
64	Cause and effect	Choose a link that shows one event producing or explaining the other.
65	Illustrative example	Choose a particular case that demonstrates a broader point.
66	Standard English conventions	Apply grammar, usage and punctuation to the sentence in context.
67	Clause boundaries	Check where an independent or dependent clause begins and ends.
68	Sentence structure	Check whether the edit produces a complete, correctly joined sentence.
69	Independent clause	Identify words with a subject and verb that can stand as a sentence.
70	Dependent clause	Identify a clause that needs a main clause to complete its function.
71	Sentence fragment	Recognise words punctuated as a sentence without a complete main clause.
72	Negative sign	Include the sign when the value is below zero.
73	Round	Adjust a number to the requested precision using the next digit.
74	One possible value	Supply a single value that satisfies the given conditions.
75	Solution set	Identify the full set of values that satisfy the stated relationship.
76	Satisfies	Check that substitution makes the equation or condition true.
77	Equivalent expression	Choose an expression with the same value throughout the allowed domain.
78	Expression	Work with the requested combination of numbers, variables and operations.
79	Equation	Use or form a statement that two expressions have equal value.
80	Inequality	Use or form the required greater-than or less-than relationship.
81	System	Find values that satisfy all listed equations or inequalities together.
82	Intercept	Read the point where the graph crosses the specified axis.
83	Slope	Find vertical change divided by horizontal change.
84	Slope-intercept form	Read the rate and starting value from an equation in the form y = mx + b.
85	Constant term	Identify the part of the expression with no variable factor.
86	Coefficient	Identify the numerical multiplier of the specified variable term.
87	In terms of	Express the answer using the quantities named in the question.
88	Per	Treat the second unit or quantity as the denominator of a rate.
89	Unit rate	Calculate the amount corresponding to one unit of the other quantity.
90	Percent increase	Divide the increase by the starting value and convert to a percent.
91	Percentage point	Find the simple difference between two percentage values.
92	Initial value	Find the starting quantity, often the output at input zero.
93	Maximum	Find the highest possible value within the conditions.
94	Minimum	Find the lowest possible value within the conditions.
95	Exactly	Use equality at the stated quantity.
96	Fewer than	Use a strict upper bound that excludes the stated value.
97	Greater than	Use a strict lower bound that excludes the stated value.
98	No solution	Show that no allowed value meets every condition.
99	Infinitely many solutions	Recognise when the conditions hold for an unbounded number of possible values.
100	One solution	Identify the unique value or pair satisfying the conditions.
101	Integer	Use a whole-number value that may be negative, zero or positive.
102	Positive	Restrict the value to numbers greater than zero.
103	Consecutive	Use values following one another in the stated sequence.
104	Probability	Find the likelihood of the event under the given conditions.
105	Random sample	Check how cases are selected before drawing conclusions about a population.
106	Identify a control	Name the comparison condition relevant to the claim being tested.
107	Predict the outcome	State the expected result in the conditions described.
108	Justify your prediction	Connect your proposed outcome to a mechanism or evidence that makes it plausible.
109	Construct a graph	Set up the axes, scale and labels, then represent the data in the requested form.
110	Plot the data	Place the values on the graph in the correct positions.
111	Identify the independent variable	Name the factor manipulated or selected as input.
112	Identify the dependent variable	Name the outcome that was measured.
113	Sample mean	Use the average of the values in the specified sample.
114	Standard error	Interpret it as uncertainty in an estimated statistic where the question uses that measure.
115	Error bars	Read their meaning from the figure legend before interpreting them.
116	Control treatment	Use the treatment intended to provide a reference comparison.
117	Support the claim	Give evidence that bears on the exact claim in the question.
118	Explain the result	Connect the observation to a biological, historical or other applicable reason.
119	Quantify the change	Give the size of the difference, increase or rate with its unit or percentage.
120	Mechanism	Describe the steps through which an outcome is produced.
121	Experimental design	Use the stated groups, conditions and measurements to judge the experiment.
122	Sample size	Check how many observations or individuals contribute to the result.
123	Variable	Identify a quantity or feature that can change.
124	Independent variable	Identify the factor changed or selected as the input.
125	Dependent variable	Identify the outcome measured or modelled.
126	Controlled variable	Identify a factor kept constant to help isolate the tested relationship.
127	Raw data	Use the measurements as originally collected.
128	Processed data	Use values calculated, combined or transformed from the original readings.
129	Uncertainty	State or interpret the estimated doubt associated with a measurement or value.
130	Absolute uncertainty	Express the estimated uncertainty in the same units as the quantity.
131	Axis label	Read which quantity or group the axis represents before comparing values.
132	Outlier	Identify an observation unusually far from the general pattern.
133	Anomalous result	Recognise a result inconsistent with the main pattern or expected relationship.
134	Reliability	Consider whether a result or method gives consistent findings.

Core commands and evidence

No.	Instruction or term	What it asks you to do
135	Recognise	Find a familiar feature in a new example.
136	Identify	Name or pick out the item the question specifies.
137	Select	Choose only the number of options requested.
138	Choose	Commit to the option that fits the stated criteria.
139	Match	Pair each item with the option that corresponds to it.
140	Complete	Fill in what is missing while keeping the supplied structure.
141	Label	Attach the correct name to the indicated part.
142	Locate	Find the specified detail, point or region.
143	Indicate	Make the chosen feature or answer clear.
144	Answer	Respond directly to the question being asked.
145	Give	Supply the requested fact, example or result.
146	State	Express the required point directly and clearly.
147	Name	Supply the correct term, person or item.
148	List	Set out the requested items separately.
149	Define	Give the precise meaning used in the subject or question.
150	Describe	Report the relevant characteristics, events or pattern.
151	Outline	Give the main steps or points in brief.
152	Summarise	Select the central points and leave out minor details.
153	Explain	Connect the result to its cause, mechanism or reasoning.
154	Compare	Set the items side by side on the same relevant feature.
155	Contrast	Show how the items differ on a shared point of comparison.
156	Analyse	Break down the evidence and explain how its parts relate.
157	Interpret	Say what a statement, result or display means in context.
158	Infer	Use clues to reach a conclusion the material implies.
159	Predict	Use available evidence to say what is likely to happen.
160	Suggest	Offer a plausible answer suited to the information given.
161	Justify	Give evidence or reasoning that supports your answer.
162	Evaluate	Weigh relevant evidence or criteria before reaching a judgment.
163	Assess	Judge the extent, value or strength of something using evidence.
164	Discuss	Develop a structured response that considers the relevant issues.
165	Distinguish	Give the feature that lets the reader tell two things apart.
166	Support	Supply evidence that helps establish the claim.
167	Illustrate	Make an idea clear with a relevant example or diagram.
168	Demonstrate	Show how a fact, process or result can be established.
169	Determine	Work from the given information to establish an answer.
170	Calculate	Use numbers or other given information to work out a result.
171	Estimate	Find an approximate answer using the available clues.
172	Check	Test the answer against the original instruction or condition.
173	Correct	Repair the specific error while preserving the intended meaning or result.
174	Revise	Change a response so it better meets the task.
175	Arrange	Put items into the order or grouping requested.
176	Sequence	Put stages into a meaningful order.
177	Group	Put items with a shared feature together.
178	Replace	Swap the specified part for a suitable alternative.
179	Omit	Leave out the indicated item or detail.
180	Include	Make sure the requested part appears in the response.
181	Exclude	Keep the named item or category outside your answer.
182	Refer to	Use the specified passage, figure or notes when responding.
183	Based on	Ground the answer in the material named in the question.
184	According to	Use what the specified source says.
185	In context	Use the meaning that fits this passage or situation.
186	Most likely	Choose the conclusion with the strongest support among the options.
187	Best supported	Prefer the conclusion backed most directly by the evidence.
188	Relevant	Connected to the specific question or criterion.
189	Specific	Precise enough to identify a particular fact or example.
190	Explicit	Stated directly in the source.
191	Implicit	Suggested by the source and recoverable from clues.
192	Evidence	A fact, detail or observation that supports a claim.
193	Claim	An assertion that can be tested against evidence or reasoning.
194	Reason	The basis for a statement, choice or result.
195	Example	A particular case used to make a general idea clear.
196	Conclusion	The result reached after considering the reasoning or evidence.
197	Assumption	A premise taken as given for the purpose of the question.
198	Condition	A requirement that must be satisfied.
199	Constraint	A restriction that shapes the possible answers.
200	Criterion	A standard used to choose or judge an answer.

What the examination requires

Use the directions for your ACT administration

The ACT is a U.S. college admissions test also administered internationally. ACT says the updated Composite uses English, Math and Reading. Science is optional in the enhanced format and ACT also offers a separate Writing test. Confirm options and procedures for your administration and check the requirements of the institutions receiving your scores.

International enhanced content began in February 2026

ACT’s non-U.S. page separates the September 2025 introduction of the revised Composite and optional Science from the February 2026 introduction of enhanced international test content. Use current international practice materials to learn pacing and the instructions you will see. Some school or district arrangements can differ.

English, Math and Reading require distinct checks

English includes decisions about the production of writing, language and standard conventions. Math requires solving or interpreting the stated problem. Reading asks for meaning and evidence in passages. In an English edit, a grammatical option can still fail if the question asks for a specific tone or writing purpose. The official overview lists English at 50 questions in 35 minutes, Math at 45 in 50 minutes and Reading at 36 in 40 minutes. Check the directions for your particular administration.

Optional Science and Writing have separate jobs

Science questions can ask you to interpret data, read an investigation or judge competing viewpoints. The Writing task asks for a developed position on an issue and engagement with the perspectives as directed. If you take either section, practise its own instructions and review the official score reporting information.

• Mark the action and the material it applies to.
• Check the required number or length of responses.
• Use the official test format when you rehearse timing.

Worked examples of common examination instructions

These original examples show how changing a few words in a prompt can change what belongs in the answer.

Test an edit against the stated purpose

An original practice paragraph introduces a workshop on repairing bicycles. The instruction asks which sentence best explains what beginners will learn. A sentence saying participants will practise adjusting brakes and fixing a puncture meets the goal. A true sentence about how many bicycles the organiser owns does little for that goal.

Choose a transition using the real relationship

One sentence says a team hoped to reduce waiting times. The next says waiting times rose for the first month. The second idea contrasts with the expectation. A contrast transition fits if its grammar also works with the surrounding clauses.

Read the quantity the math question asks for

A bicycle rental costs $8 plus $3 per hour. After four hours, the total is $20, but the hourly rate is $3. If the question asks which number represents the initial charge, use $8. Label the quantities before choosing an answer so a correct calculation does not become an answer to the wrong question.

Separate competing viewpoints in Science

Imagine one model predicts higher germination as temperature rises, while another predicts a peak followed by a decline. Data rising to 24°C and then falling support the peak model more directly. Compare both predictions using the same observed pattern.

Engage with a Writing perspective

If one perspective says public libraries should prioritise quiet study and another emphasises group learning, you could argue for separate zones. Explain how the policy preserves quiet work and enables discussion, then address a practical limitation such as limited floor space.

Use the Fencing Method to practise instruction words

Start with a short accurate sentence. Add a precise detail and then the relationship the task asks for. Practise the same instruction on fresh material. For selected-response items, the sentence is a practice step that helps you decide which option fits.

1. The edit fits the goal.
2. The edit tells beginners what they will learn.
3. The edit names two skills beginners will practise, so it meets the passage’s goal of introducing the workshop.
4. Apply the same check to a different passage. State the goal before choosing an edit and connect the choice to that goal.

Read the eduKate Fencing Method for Vocabulary.

Practise and check your answers

Practise reading for a purpose before editing

Before looking at the options, restate the editorial goal in plain English. Then compare each option against that goal and the surrounding grammar. For Reading, distinguish questions about one sentence from questions about the whole passage.

Review data and maths items by their last line

Read the final sentence again after solving. Check what quantity it requests and which units or groups apply. On Science practice, write the predicted pattern of each model beside the measured pattern. Mark exactly where the evidence supports or challenges a model.

Practice 1. An answer option is labelled NO CHANGE. When should you choose it?

Choose it when the original text is the best response to the question and works in context.

Practice 2. A passage question asks for the function of one paragraph. What should you explain?

Identify what the paragraph does within the passage, such as providing an example or presenting a contrast.

Practice 3. If a graph uses minutes on its horizontal axis, what should you check before selecting a rate?

Check whether the rate is required per minute or in another time unit, and convert if the question asks.

Practice 4. A Science item asks which result supports a model. What do you compare first?

Compare the predicted pattern and observed pattern on the same quantities and conditions.

Frequently asked questions

Is the ACT Science section included in the current core Composite?

ACT describes the enhanced Composite as using English, Math and Reading. Check its reporting guidance for Science and STEM scores.

Can I practise with an older paper?

Use it for content practice where appropriate. Use current enhanced materials to learn the format for your test date and administration.

Is a correct fact always the best English answer?

If the question names a rhetorical goal, choose the accurate wording that best serves that goal.

Official sources and next reading

• ACT enhancements for international candidates
• ACT official sections, structure and timing
• ACT official test preparation
• ACT enhanced test FAQs

Related guide in this series · Digital SAT examination instructions

Read eduKateSG’s 200-word vocabulary guide for more ways to group and practise vocabulary.

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