Sentence Structure

• Recognize sentence fragments in a quick complete-or-incomplete round of about ten short sentences, including long ones with no main verb and short ones that are complete
• Identify and correct run-on sentences and comma splices with the split-at-the-mark test from Commas and Semicolons
• Apply parallel structure to the items in a list or series
• Identify and correct misplaced modifiers (too far from what they describe) and dangling modifiers (no logical subject)
• Finish on one ACT-hard question and say what made it hard

A fragment lacks a subject, a verb, or a complete thought. A run-on sentence fuses two independent clauses without proper punctuation or a conjunction; a comma splice is a specific type of run-on that uses only a comma. Fix run-ons by adding a period, semicolon, or comma + coordinating conjunction; these are the same clause-joining rules covered in the Commas and Semicolons lesson, so review them together. Parallelism requires that items in a series share the same grammatical form: 'She likes swimming, hiking, and *biking*' (not 'to bike'). On the ACT, parallel structure errors most often hide in lists of three or more items, so check that every item starts with the same kind of word. Modifier errors are another frequent trap. A misplaced modifier sits next to the wrong word: 'She served sandwiches to the children on paper plates' seems to put the children on the plates, so move the phrase: 'She served the children sandwiches on paper plates.' A dangling modifier has no logical subject in the sentence at all: '*Running quickly,* the finish line came into view' (the finish line is not running). Fix it by putting the runner right after the comma: '*Running quickly,* she saw the finish line.' Modifier questions show up regularly on the English section. Use the boundary test from the Commas and Semicolons lesson here too: split at the mark and ask 'complete thought?' of each side. Length does not make a sentence complete; a subject and a main verb do. The ACT-hard version: one choice quietly turns the main verb into an -ing form ('hauling' for 'hauled') and creates a fragment, or a long subject with a 'who' clause and a pile of phrases never reaches its verb.

• If an answer choice creates a fragment by turning a clause into a participial phrase (e.g., replacing 'she ran' with 'running'), it is likely wrong.
• Two independent clauses joined by only a comma is always wrong on the ACT. Look for a conjunction or stronger punctuation.
• For parallelism, underline each item in a list and check that they start with the same part of speech.