Function words

In English grammar  a function word is word  that expresses a grammatical or structural relationship with other words in a senetnce.

Function words are also known as:

• structure words
• grammatical words
• grammatical functors
• grammatical morphemes
• function morphemes
• form words
• empty words

According to James Pennebaker, "function words account for less than one-tenth of 1 percent of your vocabulary but make up almost 60 percent of the words you use."

Function words include determiners, conjunctions, prepositions, pronouns, auxiliary verbs, modals, qualifiers, and question words. Content words are words with specific meanings, such as nouns, adjectives, adverbs, and main verbs (those without helping verbs.) In the sentence, "The sly brown fox jumped gracefully over the lazy dog and cat," the content words are:

• fox, dog, and cat (nouns)
• sly, brown, and lazy (adjectives)
• gracefully (adverb)
• jumped (main verb)

Function words include:

• the (determiner)
• over (preposition)
• and (conjunction)

Even though the function words don't have concrete meanings, sentences would make a lot less sense without them.

Determiners are words such as articles (the, a), possessive pronouns (their, your), quantifiers (much), demonstratives (that, those), and numbers. They function as adjectives to modify nouns and go in front of a noun to show the reader whether the noun is specific or general, such as in "that coat" (specific) vs. "a coat" (general). 

• Articles: a, an, the
• Demonstratives: that, this, those, these
• Possessive pronouns: my, your, their, our, ours, whose, his, hers, its, which 
• Quantifiers: some, both, most, many, a few, a lot of, any, much, a little, enough, several, none, all

Conjunctions connect parts of a sentence, such as items in a list, two separate sentences, or clauses and phrases to a sentence. In the previous sentence, the conjunctions are or and and.

• Conjunctions: and, but, for, yet, neither, or, so, when, although, however, as, because, before 

Prepositions begin prepositional phrases, which contain nouns and other modifiers. Prepositions function to give more information about nouns. In the phrase "the river that flows through the woods." The prepositional phrase is "through the woods," and the preposition is "through."

• Prepositions: in, of, between, on, with, by, at, without, through, over, across, around, into, within

Pronouns are words that stand in for nouns. Their antecedent needs to be clear, or your reader will be confused. Take "It's so difficult" as an example. Without context, the reader has no idea what "it" refers to. In context, "Oh my gosh, this grammar lesson," he said. "It's so difficult," the reader easily knows that it refers to the lesson, which is its noun antecedent.

• Pronouns: she, they, he, it, him, her, you, me, anybody, somebody, someone, anyone

Auxiliary verbs are also called helping verbs. They pair with a main verb to change tense, such as when you want to express something in present continuous tense (I am walking), past perfect tense (I had walked), or future tense (I am going to walk there). 

• Auxiliary verbs: be, is, am, are, have, has, do, does, did, get, got, was, were

Modal verbs express condition or possibility. It's not certain that something is going to happen, but it might. For example, in "If I could have gone with you, I would have," modal verbs include could and would.

• Modals: may, might, can, could, will, would, shall, should

Qualifiers function like adverbs and show the degree of an adjective or verb, but they have no real meaning themselves. In the sample sentence, "I thought that somewhat new dish was pretty darn delicious," the qualifiers are somewhat and pretty.

• Qualifiers: very, really, quite, somewhat, rather, too, pretty (much)

It's easy to guess what function that question words have in English. Besides forming questions, they can also appear in statements, such as in "I don't know how in the world that happened," where the question word is how.

• Question words: how, where, what, when, why, who