Words on Writing: F

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figure of speech

A colorful expression with idiomatic meaning, a turn of phrase: Dog my cats! (“I’ll be dipped!”).

Compare rhetorical device.

filler word

A word that contributes no meaning—and, therefore, typically no value—to a phrase or sentence.

Two types of filler words to delete (usually) are qualifiers and expletives. In Vera feels somewhat cold, the qualifier somewhat adds no value. In There is no reason to turn the heat down, the expletive there adds no value. Better: Vera feels cold. Don’t turn the heat down.

A filler word may add value in terms of meter or sound. The Nat King Cole lyric “V is very, very extraordinary” would be tough to sing without the filler verys.

For more, see the chapter “The Pen Is Mightier than the Shovel” in Word Up!

foot, metrical

See metrical foot.


A word’s physical shape, the aspect of the word that you see or hear. Every word has form. The form of the word sidewalk is s‑i‑d‑e‑w‑a‑l‑k. If you add or delete or change the letters—whether meaningfully (sidewalks) or randomly (sidewalkqwerty or qwertysidewalk or sdqwertywks)—you change its form. Going (go+ing) is a form of the verb to go. Went is also a form of to go. Because went falls outside the standard pattern of verb conjugation (past tense = <verb>+ed), went is called an irregular form of the verb.

Compare function.

For more, see the chapter “A Modern Take (Is Take a Noun?) on Parts of Speech” in Word Up!

form-class words (content words, parts of speech)

Words in any of the form classes: nouns (house), verbs (welcomed), adjectives (warm), and adverbs (warmly). Modern linguists consider these classes—only these four—the parts of speech. Form-class words, or content words, usually contain not grammatical meaning (as structure-class words do) but lexical meaning, that is, meaning in themselves.

Form-class words, the majority of English words, have something in common that sets them apart from words in the structure classes: they generally change form in characteristic ways. In isolation (out of context), these words can be linguistically tested in ways that help classify them. For example, adding an s transforms a noun into a plural that English speakers would use naturally (house+s = houses), and adding est transforms an adjective into a superlative (warm+est = warmest).

When a single word changes form in ways characteristic of a given form class, linguists call that word a noun, verb, adjective, or adverb in form.

While some words never stray from a single form class—desk, for example, is a prototypical noun (you wouldn’t normally say, “We’re desking” or “That’s the deskest”)—many English words can belong to multiple form classes. House belongs to two form classes: nouns and verbs. It changes form in ways characteristic of nouns (houses, house’s), so it qualifies as a noun in form—and it changes form in ways characteristic of verbs (housed, housing), so it also qualifies as a verb in form.

Self-proclaimed enigmatologist Will Shortz, crossword-puzzle editor for the New York Times and consummate creator of duplicitous clues, has built his following on the backs of words like this—words that move easily between form classes. Take the tease of a clue Defeat in a derby. Are we meant to read defeat as a noun (as in “a defeat in a derby”) or as a verb (“to defeat in a derby”)? The clue alone lacks sufficient context. We have to fill in some neighboring answers to determine the answer: “outride” (a verb—aha!). In some puzzles, the same clue appears multiple times, yielding answers from multiple form classes. The clue mean might appear twice, yielding a noun (“average”) for one answer and a verb (“signify”) for another. In crossword puzzles, as in everyday usage, a form-class word holds clues within itself but reveals its full meaning only in the context of other words.

For more, see the chapter “A Modern Take (Is Take a Noun?) on Parts of Speech” in Word Up!


See sentence fragment.


The grammatical role that a word or phrase plays in a phrase or sentence. Sidewalk functions as (acts as) a direct object in Let’s shovel this sidewalk and as an adjective in I’ve got the sidewalk blues. Just as a musical note’s function in a chord is determined by its position relative to the other notes—the same note contributes to a major chord here, a minor chord there—a word’s or phrase’s function in a phrase or clause is determined largely by its position relative to the other words.

Compare form.

For more, see the chapter “A Modern Take (Is Take a Noun?) on Parts of Speech” in Word Up!

function words

See structure-class words.

fused sentence

A run-on sentence that includes two independent clauses joined by only a space: Max bent down to pick up the rock he heard his back snap.

Compare comma-spliced sentence.

A-Z page

This is not a list of all words about writing—you’d be scrolling all day. These definitions evolved while I was writing Word Up! I enjoyed what I learned and wanted to share it.

Get the full glossary and more in the book: Word Up! How to Write Powerful Sentences and Paragraphs (And Everything You Build from Them)

Last modified: October 21, 2022