Gerund

A gerund is the -ing form of a verb used as a noun. In "Running clears my head," the word running names an activity and serves as the subject of the sentence — it is a gerund. Gerunds let you treat actions as things, which is why they can do every job a noun does: subject ("Reading builds vocabulary"), direct object ("She enjoys reading"), or object of a preposition ("He improved by reading daily").

The tricky part is that not every -ing word is a gerund. The same form can be a present participle acting as part of a verb phrase ("She is reading") or as an adjective ("a reading lamp"). The test is function: if the -ing word is doing the work of a noun, it is a gerund; if it is showing ongoing action or describing a noun, it is a participle. "Cooking relaxes me" (gerund) versus "I am cooking dinner" (participle) makes the contrast clear.

Gerunds also anchor several usage rules that tests love. Certain verbs take a gerund rather than an infinitive ("avoid waiting," not "avoid to wait"), prepositions are followed by gerunds ("interested in learning"), and formal English uses a possessive before a gerund ("We appreciated his calling ahead").

Standardized tests including the SAT, CLT, and Praxis Core Writing exam test gerunds within their grammar and verb-form questions. Expect items that ask you to distinguish a gerund from a participle, choose between a gerund and an infinitive after a given verb, or recognize that a gerund phrase is acting as a single noun for subject-verb agreement purposes.