ACT · English · Conventions of Standard English

Punctuation

Punctuation is part of Conventions of Standard English in the ACT English section. The questions below are written in the style of the real test, each with the answer and a worked explanation.

Question types you will see here include unnecessary comma between sentence parts, non-essential element needs a matching pair, possessive versus plural apostrophe, its / it's, whose / who's and your / you're.

Common traps: a comma between the subject and the verb; a comma after that or because with nothing to set off; a comma before the second half of a compound predicate.

Sample questions

Question 1
Ada Lovelace, the daughter of the poet Lord Byron wrote what many consider the first computer program.
Which choice is best for the underlined portion? If the original is best, choose NO CHANGE.
- A.
  NO CHANGE
- B.
  Byron, wrote
- C.
  Byron—wrote
- D.
  Byron; wrote
Answer: B. Byron, wrote
The element "the daughter of the poet Lord Byron" is nonessential information inserted between the subject and the verb. Because it opens with a comma, it must close with the same mark. Omitting the punctuation, using a semicolon, or mixing a comma with a dash is incorrect.
Question 2
Two weeks' worth of groceries filled the pantry.
Which choice is best for the underlined portion? If the original is best, choose NO CHANGE.
- A.
  NO CHANGE
- B.
  week's
- C.
  weeks's
- D.
  weeks
Answer: A. NO CHANGE
Two weeks is plural, so the plural possessive "weeks'" is required in this expression of time.
Question 3
The desert appears lifeless during the day; however dozens of species emerge to feed after sunset.
Which choice is best for the underlined portion? If the original is best, choose NO CHANGE.
- A.
  NO CHANGE
- B.
  day; however, dozens
- C.
  day, however, dozens
- D.
  day however, dozens
Answer: B. day; however, dozens
"However" is a conjunctive adverb joining two independent clauses. It must be preceded by a semicolon (or period) and followed by a comma. Using only commas creates a comma splice; omitting the comma after "however" or the semicolon before it is also incorrect.
Question 4
The seeds require a period of cold before they will sprout, as a result, many gardeners chill them in a refrigerator before planting.
Which choice is best for the underlined portion? If the original is best, choose NO CHANGE.
- A.
  NO CHANGE
- B.
  sprout; as a result, many
- C.
  sprout; as a result many
- D.
  sprout as a result, many
Answer: B. sprout; as a result, many
"As a result" is a conjunctive adverb joining two independent clauses. It must be preceded by a semicolon (or period) and followed by a comma. Using only commas creates a comma splice; omitting the comma after "as a result" or the semicolon before it is also incorrect.
Question 5
The scientists first collected water samples from twelve streams, later, they tested each sample for traces of nitrogen.
Which choice is best for the underlined portion? If the original is best, choose NO CHANGE.
- A.
  NO CHANGE
- B.
  streams later, they
- C.
  streams; later, they
- D.
  streams; later they
Answer: C. streams; later, they
"Later" is a conjunctive adverb joining two independent clauses. It must be preceded by a semicolon (or period) and followed by a comma. Using only commas creates a comma splice; omitting the comma after "later" or the semicolon before it is also incorrect.

Find your real gaps

A few questions show the style. The free scan shows which ACT skills cost you the most points, then builds a plan around them.

Take the free scan