Your FREE ACT Flashcards 2026 – 250+ Cards

A verb must match its subject in number. Ignore words between them: 'The list of items IS missing' (subject = list).

The error of joining two independent clauses with only a comma. Fix with a period, semicolon, or comma + FANBOYS.

The seven coordinating conjunctions — For, And, Nor, But, Or, Yet, So — that join two independent clauses after a comma.

A group of words with a subject and verb that can stand alone as a complete sentence.

A clause that cannot stand alone (begins with words like because, although, when, which).

To join two related independent clauses without a conjunction. It works wherever a period would.

To introduce a list, explanation, or quotation — but only after a complete sentence.

A descriptive phrase with no clear word to modify, so it seems to describe the wrong noun.

A modifier placed too far from the word it describes, changing the intended meaning.

Items in a list, comparison, or series share the same grammatical form (reading, writing, and running).

A pronoun must match the noun it refers to in number and gender, with a clear reference.

'its' is possessive (no apostrophe); 'it's' = it is or it has. Test by expanding to 'it is.'

'your' is possessive; 'you're' = you are.

'their' = possessive; 'there' = place; 'they're' = they are.

'who' is a subject (does the action); 'whom' is an object (receives it). Test with he/him.

Singular noun adds 's (dog's); plural noun ending in s adds just ' (dogs'). Plurals take no apostrophe.

Two or more independent clauses joined with no proper punctuation or conjunction.

A group of words punctuated as a sentence but missing a subject, verb, or complete thought.

Keep verb tenses consistent within a sentence and passage unless the timeline truly changes.

ACT English reporting category (38–43%): topic development, organization, unity, and cohesion.

ACT English reporting category (18–23%): precise word choice, style, tone, and concision.

ACT English reporting category (38–43%): grammar, usage, punctuation, and sentence structure.

Saying the same thing twice ('return back,' 'each and every'). The ACT usually rewards cutting it.

However, but, nevertheless, on the other hand — signal a change in direction.

Therefore, thus, consequently, as a result — signal a result.

Moreover, furthermore, in addition, also — add a related idea.

Decide based on whether the sentence supports the paragraph's stated purpose — relevance, not interest.

Set off nonessential (extra) information with a pair of commas; essential information takes no commas.

Never place a comma between a subject and its verb.

A legitimate answer chosen about a quarter of the time — pick it when the original is already correct and concise.

'affect' is usually a verb (to influence); 'effect' is usually a noun (a result).

'then' = time/sequence; 'than' = comparison.

When two choices are both grammatical, the shorter, clearer one is usually correct.

Often the correct, most-concise answer on the ACT when the text is redundant or off-topic.

Standard preposition that follows a word ('interested IN,' 'capable OF'). The ACT tests these.

Restrictive (essential) clauses take no commas and often use 'that'; nonrestrictive (extra) clauses use commas and 'which.'

Use 'that' for essential clauses (no comma); 'which' for nonessential clauses (set off by commas).

A colon introduces (a list/explanation after a complete clause); a semicolon joins two complete clauses.

A pair of dashes (or one dash) can set off a nonessential element or signal an abrupt break or emphasis.

For a plural noun ending in s, add only an apostrophe: the students' scores.

These are singular and take a singular verb (Each of the students is ready).

Subjects joined by 'and' take a plural verb; 'or'/'nor' agree with the nearer subject.

Use object pronouns (me, him, her, them) after a preposition: 'between you and me.'

'Fewer' for countable items (fewer questions); 'less' for uncountable amounts (less time).

Comparative compares two (taller); superlative compares three or more (tallest).

Compare like things: 'Her score is higher than his' (not 'than him').

Don't shift needlessly between indicative, imperative, and subjunctive within a sentence.

Pick the version that joins ideas most clearly and concisely without creating a run-on.

Order sentences so each follows logically; watch transition and pronoun cues that fix position.

Choose the detail that best fits the paragraph's focus; reject vague or off-topic additions.

Keep the register consistent with the passage — formal stays formal, no slang in a formal essay.

Avoid two negatives in one clause ('didn't do nothing'); it's nonstandard.

Reject a pronoun (it, this, they) whose antecedent is unclear; the ACT wants a clear reference.

Words like however and therefore between two clauses need a semicolon before and a comma after.

'whose' is possessive; 'who's' = who is.

m = (y₂ − y₁) / (x₂ − x₁) — the change in y over the change in x (rise over run).

y = mx + b, where m is the slope and b is the y-intercept.

y − y₁ = m(x − x₁), using a point (x₁, y₁) and the slope m.

Parallel lines share a slope; perpendicular slopes are negative reciprocals (m and −1/m).

For a right triangle, a² + b² = c² (legs a and b, hypotenuse c).

3-4-5, 5-12-13, 8-15-17 (and their multiples).

Side ratio 1 : 1 : √2 (legs equal; hypotenuse is a leg times √2).

Side ratio 1 : √3 : 2 (short leg : long leg : hypotenuse).

x = (−b ± √(b² − 4ac)) / (2a), for ax² + bx + c = 0.

b² − 4ac: positive = 2 real solutions, zero = 1, negative = 0 real solutions.

Multiply two binomials: First, Outer, Inner, Last. (x+2)(x+3) = x² + 5x + 6.

a² − b² = (a + b)(a − b).

A = πr².

C = 2πr (or πd).

A = ½ × base × height.

A = length × width; perimeter = 2(length + width).

V = length × width × height.

V = πr²h.

sin = opposite/hypotenuse, cos = adjacent/hypotenuse, tan = opposite/adjacent.

d = √((x₂ − x₁)² + (y₂ − y₁)²).

((x₁ + x₂)/2, (y₁ + y₂)/2).

The average — the sum of values divided by how many there are.

The middle value of an ordered set (average the two middle values if the count is even).

The value that appears most often in a data set.

The largest value minus the smallest value.

Favorable outcomes ÷ total possible outcomes — a value from 0 to 1.

(new − old) ÷ old × 100. Always divide by the original.

Convert the percent to a decimal and multiply (25% of 80 = 0.25 × 80 = 20).

xᵃ × xᵇ = xᵃ⁺ᵇ (add exponents when multiplying like bases).

xᵃ ÷ xᵇ = xᵃ⁻ᵇ (subtract exponents when dividing like bases).

(xᵃ)ᵇ = xᵃᵇ (multiply the exponents).

x⁻ⁿ = 1 / xⁿ.

Any nonzero number to the 0 power equals 1.

A rule giving exactly one output for each input x; f(2) means substitute 2 for x.

Domain = all valid inputs (x); range = all resulting outputs (y).

y = kx — y changes in proportion to x (k is the constant).

y = k/x — as x increases, y decreases.

180°.

360°.

Supplementary add to 180°; complementary add to 90°.

Use substitution or elimination to find values that satisfy both equations.

|x| is the distance from 0, always non-negative. |x| = a means x = a or x = −a.

Horizontal line slope = 0; vertical line slope is undefined.

ACT Math reporting category (≈80%): Number & Quantity, Algebra, Functions, Geometry, Statistics & Probability.

ACT Math reporting category (≈20%): rates, percent, proportion, area/volume, averages in multi-step problems.

Questions that build or interpret a real-world model; also counted within other math categories.

I = principal × rate × time (P × r × t).

Total distance ÷ total time (not the average of the two speeds).

Add or subtract terms with the same variable and exponent (3x + 2x = 5x).

Equal slopes.

Negative reciprocals (e.g., 2 and −1/2).

Where a graph crosses the y-axis (x = 0); the b in y = mx + b.

Where a graph crosses the x-axis (y = 0); a root/zero of the function.

The maximum or minimum point; x = −b/(2a) for y = ax² + bx + c.

Rewrite ax² + bx + c into a(x − h)² + k form to find the vertex.

Factor out the largest common term first when simplifying or factoring.

a/b = c/d means ad = bc.

A comparison of quantities (3:4). Scale both parts by the same factor.

A rate per single unit (miles per hour, cost per item).

A number as a × 10ⁿ with 1 ≤ a < 10 (e.g., 4.2 × 10³).

√(ab) = √a × √b; √a is the non-negative root.

The distance formula comes from a² + b² = c² applied to coordinate differences.

Arc length and sector area are fractions of the whole (central angle ÷ 360°).

2(lw + lh + wh).

V = (1/3)πr²h.

V = (4/3)πr³.

Same shape, proportional sides; corresponding angles are equal.

Both equal 1/2.

Both equal √2/2.

tan θ = sin θ / cos θ = opposite / adjacent.

i = √(−1); i² = −1.

Rows × columns. A 2×3 matrix has 2 rows and 3 columns.

Multiply every entry by the scalar.

log_b(x) = y means bʸ = x.

Combinations ignore order; permutations count order.

Multiply: P(A and B) = P(A) × P(B).

Add: P(A or B) = P(A) + P(B).

Multiply each value by its weight, sum, then divide by the total weight.

A measure of how spread out data is from the mean; all-equal data has 0.

'Of' often means multiply; 'is' means equals; 'per' means divide.

Parentheses, Exponents, Multiply/Divide (left to right), Add/Subtract (left to right).

Flip the inequality sign when multiplying or dividing both sides by a negative.

|x| = a gives x = a or x = −a (a ≥ 0).

Equals the middle value (or the average of the two middle values).

The central point the whole passage supports — broader than any single detail.

A conclusion the passage implies but doesn't state directly, supported by textual evidence.

A word's meaning from how it's used in the passage — often a less common meaning.

Why the author wrote the passage (to inform, persuade, describe, entertain).

The author's attitude toward the subject, shown through word choice (e.g., critical, admiring, neutral).

The perspective the passage is told from (first person, third person; the narrator's stance).

Largest ACT Reading category (44–52%): main ideas, summary, sequence, supporting evidence.

ACT Reading category (26–33%): word meaning, point of view, text structure, and tone.

ACT Reading category (19–26%): arguments, evidence, and comparing paired passages.

Two shorter related texts with questions spanning both — summarize each author before comparing.

An ACT Reading passage type: an excerpt from a short story or novel.

An ACT Reading passage type drawing on fields like history, economics, or psychology.

An ACT Reading passage type from fields like art, literature, philosophy, or a memoir.

An ACT Reading passage type on a scientific topic written for a general reader.

Reread the cited lines plus a sentence before and after; answer from the text, not memory.

Three answers are supported by the passage and one is not; cross off what you can prove.

A fact can be verified; an opinion is a judgment or belief. The ACT asks you to tell them apart.

A specific piece of text that backs up the main idea — found, not recalled.

The order in which things happen in the passage; track time words (then, before, later).

A passage organized around similarities and differences between two things.

Cover the choices, predict your own synonym from context, then pick the closest answer.

A choice that is true of only one paragraph, not the whole passage — too narrow.

Budget ~9 minutes per passage; don't over-invest in one hard question.

Critical, skeptical, dismissive, ironic, somber — signal disapproval or seriousness.

Admiring, optimistic, enthusiastic, reverent — signal approval or warmth.

The sentence (often first) that states a paragraph's main point.

The underlying message or insight a literary passage conveys.

How an author reveals a character — through actions, words, thoughts, and others' reactions.

Mood is the feeling created in the reader; tone is the author's attitude toward the subject.

Denotation is a word's literal meaning; connotation is its emotional association.

Non-literal language — metaphor, simile, personification — used for effect.

A simile compares using like/as; a metaphor states one thing is another.

A question asked for effect, not for an answer.

The main position the author is trying to convince you of.

Asks which detail best supports a given answer or claim; cite the strongest textual proof.

Reject answers that go beyond what the passage actually supports.

Why it's there — to introduce, support, contrast, or transition.

Explicit is stated outright; implicit must be inferred.

Read the first/last sentences and topic sentences to grasp structure before the questions.

Note the main idea of each paragraph as you go to find answers faster.

Cross off answers you can disprove from the text; the survivor is usually correct.

Watch words like always, never, all, none — often too strong to be supported.

Pick the statement consistent with the author's stated position and tone.

A change in time, tone, or perspective; signal words often mark it.

Detail = a specific fact in the text; main idea = the passage's overall point.

Scientific reasoning and data interpretation — not memorized facts. Read the figures first.

ACT Science passage format: graphs and tables to interpret (≈25–35% of passages).

ACT Science passage format: descriptions of one or more related experiments (≈45–60%).

ACT Science passage format: two or more competing explanations to compare (≈15–20%).

The factor the experimenter deliberately changes (usually the x-axis).

The outcome measured in response to the independent variable (usually the y-axis).

The group that receives no treatment — the baseline for comparison.

A factor held the same across an experiment so it doesn't affect the result.

A testable proposed explanation a scientist sets out to support or refute.

As one variable increases, the other increases (an upward trend).

As one variable increases, the other decreases (a downward trend).

Estimating a value between known data points on a trend.

Extending a trend to estimate a value beyond the known data points.

Largest ACT Science category (40–50%): reading values, trends, and relationships from figures.

ACT Science category (20–30%): experimental design, procedures, and variables.

ACT Science category (25–35%): judging hypotheses, predictions, and conclusions.

Check the axis labels and units before reading any value.

Treat it like a Reading passage: summarize each viewpoint, then match supporting/weakening evidence.

A relationship between variables doesn't prove one caused the other.

Match the data trend to what the hypothesis predicts; the supporting answer agrees with the prediction.

Find the row/column the question names, then read straight across or down to the value.

A line of best fit shows the overall direction (positive, negative, or none) of the data.

Yes — it's the most reading-heavy format, so do it when you're fresh or last if time is short.

A small number of Science questions need basic prior science; most are answered from the figures.

Ask what variable changed between them and how the results differ as a result.

A change in units (e.g., mL vs L) changes the value — always check before answering.

Use it to predict values and judge whether the relationship is positive or negative.

Match the correct line/legend key before reading a value.

Why an experiment keeps other factors fixed — so only the tested variable's effect shows.

Repeating trials to confirm results and reduce the effect of random error.

Strengthening data fits a viewpoint's prediction; weakening data contradicts it.

Identify where two viewpoints agree and where they differ before answering.

Watch for a point where a graph changes direction (increasing to decreasing).

The highest or lowest point of the plotted data — read its coordinates.

If doubling X doubles Y, the relationship is directly proportional.

The control is unchanged; the variable is what's tested against it.

A result is the raw data; a conclusion is the interpretation drawn from it.

Pick the experiment whose design isolates the factor the question asks about.

A point far from the trend; note it but don't let it distort the overall pattern.

Estimate an in-between value by interpolating from the rows above and below.

Convert to consistent units before comparing values across a table.

The figure type changes; the relationship does not — read whichever the question references.

An unstated condition the design relies on; questions may ask you to identify it.

Predict the outcome by following the established trend in the data.

Mostly graph/table reasoning; only basic biology, chemistry, physics, and Earth science as background.

The main ACT score, 1–36 — the average of the English, Math, and Reading section scores, rounded to the nearest whole number.

No. On the Enhanced ACT, Science is optional and does not affect the Composite. If taken, it gives a separate Science score and a STEM score.

The updated ACT (2025–2026): shorter, fewer questions, Science optional, and the Composite based only on English, Math, and Reading.

English, Mathematics, and Reading — the three sections that count toward the 1–36 Composite.

Science (separate Science + STEM score) and Writing (separate 2–12 essay score). Neither affects the Composite.

131 — English 50, Math 45, Reading 36 — in 125 minutes total.

50 questions in 35 minutes.

45 questions in 50 minutes; a calculator is allowed.

36 questions in 40 minutes.

40 questions in 40 minutes (optional section).

One essay in 40 minutes; scored 2–12, separate from the Composite.

Each section is scored 1–36.

Average the English, Math, and Reading scores and round to the nearest whole number. A .5 rounds up.

An optional score (1–36) reported only if you take Science — the average of your Math and Science scores.

An optional score reported only if you take Writing — the average of English, Reading, and Writing.

A new Composite built from your highest English, Math, and Reading section scores across multiple test dates.

Section scores signaling college readiness: English 18, Math 22, Reading 22, Science 23.

About 19–20 (most recent graduating class ≈ 19.4).

Four (the Enhanced ACT dropped Math from five choices to four).

No — the ACT has no pass/fail. Colleges set their own target score ranges.

Up to 12 times.

About 70 dollars for the core test (English, Math, Reading); +5 for Science, +25 for Writing.

50 questions in 35 minutes ≈ about 36 seconds per question.

About 9 minutes per passage (36 questions in 40 minutes).

Always — there is no penalty for wrong answers, so never leave a question blank.