Gerunds vs. Infinitives in Parallel Structure: Matching Verb Forms in Series

Gerunds function as nouns: running, swimming, studying. Infinitives also function as nouns: to run, to swim, to study. In parallel series, choose one form and stick with it. Mixing gerunds and infinitives in the same series breaks parallel structure and sounds awkward. Example error: "I like running and to swim." (Running is gerund; to swim is infinitive—mixed.) Correct: "I like running and swimming" (both gerunds) or "I like to run and to swim" (both infinitives).

The choice between gerunds and infinitives sometimes depends on the verb introducing the series. Some verbs take gerunds naturally (enjoy, finish, avoid); some take infinitives (want, hope, plan). However, within a series, parallel structure requires matching forms.

Example 1 (error): "The team aims to improve, to develop skills, and winning games." (Mismatch: infinitives then gerund.) Correction: "The team aims to improve, to develop skills, and to win games." (All infinitives.) Example 2 (error): "She enjoys reading books, exercising daily, and to travel." (Mismatch: gerunds then infinitive.) Correction: "She enjoys reading books, exercising daily, and traveling." (All gerunds.) Example 3 (error): "The program teaches planning, implementation, and to evaluate outcomes." (Mismatch: nouns then infinitive.) Correction: "The program teaches planning, implementing, and evaluating outcomes." (All gerunds or all nouns.) Each example shows how matching verb forms create correct parallel structure.

A helpful pattern: look at the first item in the series. If it is a gerund, make all items gerunds. If it is an infinitive, make all items infinitives. This simple rule prevents most parallelism errors.

Practice 15 sentences daily for four days with parallel structures needing gerund or infinitive correction. Identify the first verb form in each series, then ensure all remaining items match. This habit builds automaticity so form-matching becomes instant.

After four days of daily practice, test yourself on 20 mixed parallel-structure sentences. Aim for 100% accuracy in 4 minutes. Speed and accuracy will grow together.

On test day, when you see a series of actions or items, check whether the verb forms match. SAT writers deliberately create form mismatches to test your parallel-structure sensitivity. The trap is not obvious to careless readers; catching it requires active attention. Example: "Students are responsible for attending class, completing assignments, and passing exams." (Attending and completing are gerunds; passing is also a gerund—correct.) If the test writer wanted to create an error, they might write "passing" as "to pass" (infinitive), breaking the pattern.

On test day, apply this one-sentence check: "Do all items in this series use the same verb form?" If not, identify which form is wrong and needs to match the others. This binary decision catches the error and guides correction.