ACT English — punctuation, one sentence at a time

The English section of the ACT is mostly punctuation, and punctuation is mostly one question asked over and over: can each side of this mark stand on its own as a sentence? Almost everything follows from the answer.

Two complete sentences cannot be held together by a comma. They need a semicolon, a period, or a comma with a joining word after it — and the reason "however" causes so much trouble is that it looks like a joining word and is not, so a comma on each side of it leaves the two halves connected by nothing at all. Two questions here work on that, and each wrong instruction is followed through to what it would actually produce.

Extra information dropped into the middle of a sentence has to be fenced off at both ends, and the commonest real-world failure is opening the fence and forgetting to close it. One question here does exactly that, and it uses a named person deliberately: a clause following a proper name cannot be the identifying kind that takes no commas, so deleting the opening comma is not an alternative repair but a second error.

The apostrophe questions separate the three jobs the mark can do and the one it never does. It marks possession and it marks a contraction; it never marks a plural. The test that settles the its-and-it's question every time is to read the word aloud as "it is" and see whether the sentence survives.

A colon may only follow words that could stand alone as a sentence, which rules it out after a verb still waiting for its object — and the question that makes this concrete also shows why the semicolons in a list of cities and countries have to stay, since replacing them with commas would turn three items into six. Two more questions concern commas that should never have been written at all, between a subject and its verb, and between a verb and the things it acts on.

One format note. The real test prints a sentence four times with slightly different punctuation and asks which is right, which cannot be reproduced in a text bank — four versions of one sentence differing by a comma are indistinguishable to the software as answer options. So each sentence here is printed once and the four options are instructions describing what to do to it. The reasoning a learner has to do is identical; only the answering is different.

Every person, firm and place is invented, and nothing is drawn from any official publication.

• Test each side of a mark for whether it could stand alone as a sentence, and choose the mark accordingly
• Recognise that "however" cannot join two sentences, and punctuate around it correctly
• Close an insertion at both ends, and know when deleting the opening comma is not an alternative
• Use the apostrophe for possession and contraction and never for a plural, with the it is test for its and it's
• Allow a colon only after words that could stand as a complete sentence
• Keep semicolons in a list whose items contain commas of their own
• Remove commas that separate a subject from its verb or a verb from its object

Written for this catalogue, with no source document. The content is the punctuation material named in ACT's own public description of the English section — usage and mechanics, covering the marks that join, separate and enclose; every sentence, option and explanation here is original, and nothing is reproduced from any ACT publication or released test. Note the format difference described in the lesson: the real test offers four punctuations of one sentence, which a text bank cannot represent, so the options here are instructions instead. Zestly is an independent study tool. It is not affiliated with ACT, which owns the test, and it is not an exam centre.