Introduction to English Grammar
by Prof. Kate Epstein


In increasing order of complexity, the units of language and grammar are:

  • letters
  • words (a collection of letters)
  • phrases (which contain more than one word but no verb)
  • clauses (which contain a subject and a verb but are not necessarily complete sentences). Clauses can be either dependent, which means that they are preceded by and depend on a word that prevents them from standing on their own as complete sentences; or independent, which means they can stand on their own as complete sentences.
  • sentences
  • paragraphs (which generally contain multiple sentences, although writers occasionally use one-sentence paragraphs for rhetorical effect)

The Parts of Speech

There are eight basic types of words-known as parts of speech-in the English language. They are:

  1. Nouns (e.g., ball, job, thing). When the noun is a named person or place (e.g., Joe Dimaggio, Greece), it is known as a proper noun.
  2. Pronouns (I, you, he, she, they). “Who” and its forms are special types of pronoun known as relative pronouns, which often form relative clauses. Third-person pronouns must have antededents, that is, nouns to which they refer. A common grammatical error is to use a whole clause, rather than a specific noun, as the antecedent of a prounoun. Pronouns used in this way are known as indefinite pronouns because they do not have a definite noun antecedent. It is usually difficult, if not impossible, to determine what exactly they refer to.
  3. Adjectives (e.g., good, bad, ugly). Adjectives modify nouns or pronouns-NOT verbs. There are two special kinds of adjectives:
    1. articles (the, a, an)
    2. possessive adjectives (my, mine, your, yours, his, her, hers, its, their, theirs, whose).
  4. Verbs, the basic form of which is the infinitive (e.g., to be, to go, to throw). Verbs rarely appear in the infinitive form; usually they are a manipulation of the infinitive (was, going, threw). When verbs do appear in the infinitive, it is usually because they are serving as complementary infinitives, so-called because the infinitive form is required to “complement” another word. For instance, in the statement “It is possible to imagine a better world,” “to imagine” serves as the complementary infinitive of “possible.”

    One special form of verbs is the participle, which functions as an adjective or a predicate adjective (for the latter, see below). Participles indicate whether the verb’s action is ongoing or finished. Often, though not always, they end in “ing” (for ongoing action) or “ed” (for finished action). For instance, “throwing” is the present participle of the verb “to throw,” while “thrown” (not “throwed”) is the past participle (even though it does not end in “ed”). In this context, “present” and “past” indicate whether the action is, was, or will be ongoing or finished, not whether it happened in the past, present, or future. For instance, the statement “I was throwing the ball” uses the present participle, even though the action took place in the past, because the action of throwing was ongoing; while the statement “I will have thrown the ball” uses the past participle, even though the action will take place in the future, because the action of throwing will be finished rather than ongoing.

    Another special form of verbs is known as the gerund, which functions as a noun. Gerunds end in “ing” and therefore usually look exactly like the present participles of verbs-but they are not participles, because they function as nouns rather than as adjectives. For instance, in the statement “Throwing is fun,” “throwing” is a gerund, the subject of the verb “is.” By contrast, in the statement “Throwing is boring,” “throwing” remains a gerund, while “boring” is a present participle.

  5. Adverbs (e.g., heavily, fast, shakily). Adverbs modify verbs, adjectives, adverbs, or (occasionally) prepositional phrases-NOT nouns or pronouns. Adverbs usually, but not always, end in “ly.” (For instance, “usually” is an adverb ending in “ly,” while “always” is an adverb that does not end in “ly.”) When two prepositions are in a row (e.g., “Get out of here”-both “out” and “of” are prepositions), the first one (in this case “out”) is actually an adverb.
  6. Prepositions (e.g., of, in, into, on, onto, to, out). Prepositions take objects, known as prepositional objects. Together, prepositions and their objects are known as prepositional phrases. Prepositional phrases always modify other words. Depending on how they are used, they can be either adjectival or adverbial. For instance, in the statement “I am a person of learning,” “of learning” is an adjectival prepositional phrase because it modifies the noun “person” (or, put differently, it explains what type of person I am). By contrast, in the statement “I went to the park,” “to the park” is an adverbial prepositional phrase, because it modifies the verb “went” (or, put differently, it explains where I went).
  7. Conjunctions. “Junction” comes from the Latin meaning “to join,” so conjunctions are simply words that join other words together. They are further sub-divided into three types:
    1. co-ordinating conjunctions (e.g., and, or, but)
    2. correlative conjunctions (e.g., either/or, neither/nor, both/and, not only/but also, whether/or). One of the most common mistakes in writing is to misplace correlative conjunctions such that they are not parallel.
    3. sub-ordinating conjunctions (e.g., after, although, though, as, because, before, how, if, since, than, that, until, when, where, whereas, while). Sub-ordinating conjunctions are followed by “dependent clauses” (so-called because they “depend” on the sub-ordinating conjuction), as distinct from “independent clauses” (which stand alone, without depending on another word). One of the most common mistakes in writing is to treat a sub-ordinating conjunction followed by a dependent clause as a complete sentence, when in fact it is an incomplete sentence (a.k.a. sentence fragment).
  8. Interjections (e.g., hey, oh, ouch, um).

A helpful trick for identifying the parts of speech is to consider whether they answer the question who, what, why, where, when, or how. Words that identify a “who” or a “what” are nouns or pronouns. For instance, in the sentence, “I threw the ball to Peter,” “I,” “ball,” and “Peter” are pronouns and nouns, and they answer the question, who or what performed or received the action of throwing? Similarly, adjectives (or phrases serving as adjectives) usually answer questions along the lines of “what kind” or “what type.” For instance, in the sentence, “Peter is a good friend,” the adjective “good” answers the question, what kind of friend is Peter? By contrast, words or phrases that explain why, where, when, or how are usually adverbs or serving as adverbs (as in the case of an adverbial prepositional phrases). For instance, in the sentence “I threw the ball quickly,” “quickly” is an adverb, and it answers the question, how was the ball thrown? Similarly, in the sentence “I threw the ball in the park,” “in the park” is an adverbial prepositional phrase, and it answers the question, where was the ball thrown?

Other Concepts

Certain terms indicate types of data about the parts of speech. They are:

  • number ? refers to whether a noun, pronoun, or verb is singular (I, thing, stapler) or plural (we, things, staplers).
  • person? refers to whether a pronoun or noun is “I” (first-person), “you” (second person), or “he/she/they” (third-person).
  • case? refers to whether nouns, pronouns, and adjectives are nominative, accusative, genitive, dative, or ablative. In Latin, all five cases are used and require different words or types of word endings for all nouns, pronouns, and adjectives. Nominative is used for subjects of verbs; accusative is used for the direct objects of verbs and the objects of certain prepositions; genitive is used for the possessive; dative is used for the indirect objects of verbs and the objects of certain prepositions; and ablative is used for the objects of certain prepositions. English does not really use the ablative, and the distinctions between the other four cases relate only to pronouns and do not require as many word changes, though it is still helpful to understand the concepts.
    • I, we, he, she, they, and who are nominative
    • me, us, him, her, them, and whom are accusative or dative
    • my, mine, your, yours, his, her, hers, its, their, theirs, and whose are genitive
    • you, her, and it look the same for several cases
  • voice? refers to whether a verb is active (I kick) or passive (I was kicked).
  • tense? refers to whether a verb is present (I go), past (I went), or future (I will go). Past tense can be further sub-divided into past perfect (I have gone), past imperfect (I was going), and past pluperfect (I had gone), while future tense can be further sub-divided into future perfect (I will have gone) and future imperfect (I will be going).
  • mood? refers to whether a verb is indicative (I go), subjunctive (I could go, I would go, I should go, I might go), or imperative (Go!). (“Imperative” comes from the Latin meaning “to order.”)

Diagramming (a.k.a. Parsing) Sentences

The best, if not the only, way to learn the parts of speech is to diagram sentences, so-called because the idea is to create a diagram of the way each word in the sentence relates to the others. Traditionally, students dread the task and find it painfully boring. I suspect this tradition exists because teachers do not do a good job of explaining either the nature or purpose of diagramming sentences. It is really a sort of brain-teaser, like solving a crossword puzzle. Moreover, if, like me, you find it extremely frustrating to do something right or wrong without understanding why you were right or wrong, knowing how to diagram your sentences is very satisfying. The ability to diagram your own writing is also a pre-requisite to becoming a more sophisticated and elegant writer. Any idea can be grammatically expressed in multiple ways, and finding the best one is a matter of knowing how to manipulate grammar to suit your needs.

As you practice writing, you will find that diagramming your sentences becomes unconscious rather than conscious. You will notice that a sentence sounds awkward, and instead of thinking to yourself, “I bet I could make this better if I used a different co-ordinating conjunction,” your mind will rapidly shuffle through four different but all grammatically correct ways of expressing the idea without you needing to diagram each of the four possibilities. Reaching that point is exhilarating.

The simplest complete sentence includes a subject (the person or thing doing the action) and a verb (the action being done); it does not need to contain any other words, such as an object or modifiers. It is possible to have a one-word complete sentence, such as “Go!” Here, we have the imperative of the verb “to go,” and the subject of the verb (“you”) is implied and obvious even though it is not stated. It is also possible to have two-word complete sentences, such as “I go.” Here, “I” (a pronoun) is the subject, and “go” is the first-person singular indicative form of the verb “to go.”

The next level of complexity is to add objects to the verb-that is, words to which the action is being done. Certain verbs must take objects, in which case they are known as transitive verbs (because the action must be transited, or passed along to, an object); while other verbs must not take objects, in which case they are known as intransitive verbs (because the action must not be transited, or passed along to, an object); and some verbs can be either transitive or intransitive. Consider the verb “to kick,” which can be used either transitively or intransitively. In the sentence “I kick,” “to kick” is being used intransitively, because it has no object. In the sentence “I kick the ball,” “to kick” is being used transitively, because it has an object (the ball).

The verb “to be,” which is the most complicated verb in the English language, is a special type of intransitive verb. Do not be fooled by appearances: although it can sometimes seem to be transitive, it is always intransitive. In the sentence “I am,” it is clear that “to be” is being used intransitively. But in the sentences “I am a woman” or “I am right,” it appears that “to be” is being used transitively, with “woman” and “right” as its objects. In fact, however, “woman” and “right” are not objects but predicates. I find it helpful to think of predicates as the words to which the subject of “to be” is being equated-that is, I mentally rewrite the sentence as “I = woman” or “I = wrong.” When the predicate is a noun (like “woman”), it is known as a predicate nominative; when it is an adjective (like “right), it is known as a predicate adjective.

Forms of the verb “to be” are often used to indicate the tense of a verb. Consider the following statement: “Throwing is supposed to be boring.” There are two ways to think about the verb in that statement. Either the verb is “is supposed”; or the verb is simply “is,” with “supposed”-the past participle of the verb “to suppose”-serving as its predicate adjective.

When verbs are transitive, their objects can be either direct or indirect. This distinction simply indicates-you guessed it-whether the action is being done to the object directly or indirectly. Consider again the sentence “I throw the ball.” Here, “ball” is the direct object of the verb “to throw.” Now, if we rewrite the sentence as “I throw the ball to Peter,” “ball” remains the direct object, while “Peter” is the indirect object-the action of throwing is being done to Peter indirectly via the ball. As in this case, prepositional phrases are often used to indicate the indirect object: “to” is a preposition, and “Peter” is both the object of the preposition and the indirect object of the verb. Sometimes, however, prepositional phrases are not used to indicate the indirect object. For instance, I could rewrite the sentence as follows: “I throw Peter the ball.” Do not be deceived by the re-ordering of the words: even though “Peter” now comes right after the verb, he remains the indirect object, while “ball” remains the direct object. It is still the ball-not Peter-being thrown, and thus it is still the ball that is having the action done directly to it.

All words in a sentence besides subjects, verbs, and objects are not part of the essential syntax of the sentence (“syntax” refers to the way words combine to form phrases, clauses, and sentences) but rather modify its meaning. (Here I mean the words “essential” and “inessential” purely in grammatical terms; grammatically “inessential” parts of the sentence may be essential to the meaning.) The simplest types of modifier are adjectives and adverbs, but whole phrases and clauses can be modifiers as well.

When you diagram a sentence, the first task is to identify the essential syntax: the main subject, the main verb, and if there are any, the object(s) of the main verb. Think of any other parts of the sentence, like dependent clauses, as noise trying to distract you from locating the signals. Once you have figured out the essential syntax, then turn to understanding the inessential parts of the sentence.

Diagramming a sentence involves three activities: first, identifying what part of speech every word is; second, supplying data about each word, where necessary, such as number, mood, tense, etc.; and third, drawing parentheses and lines to identify phrases, clauses, and the relationships between them. Here are some examples:

I walked the Dog

  • I = subject; first person singular nominative pronoun
  • walked = main verb; past indicative singular
  • the = article modifying “dog”
  • dog = noun; direct object of “walk”

I could walk the dog to the park

  • I = subject; first person singular nominative pronoun
  • could walk = main verb; present subjunctive singular
  • my = first person singular possessive adjective modifying “dog”
  • dog = noun; direct object of “walk”
  • to = preposition
  • the = article modifying “park”
  • park = noun; object of the preposition “to”
  • to the park = prepositional phrase (marked off by the parenthesis) modifying “walk” (indicated by the line) by explaining where the dog was walked to.

I will toss the ball (to the friend) (whom Peter brought).

  • I = first person singular nominative pronoun; subject
  • tossed = main verb; future indicative singular
  • the = article modifying “ball”
  • ball = noun; direct object of “tossed”
  • to = preposition
  • the = article modifying “friend”
  • friend = noun; indirect object of “toss,” object of the preposition “to,” antecedent of the relative pronoun “whom”
  • whom = accusative relative pronoun; direct object of “brought”
  • Peter = noun; subject of “brought”
  • brought = verb of the relative clause; past indicative singular
  • “to the friend” = prepositional phrase. Although it serves to identify the indirect object of the verb, it could also be thought of as an adverb modifying the verb by explaining where the ball is being tossed.
  • “whom Peter brought” = relative clause modifying “friend”

While I waited for the bell to ring,  I indulged in seriously annoyed grumbling at the delusions of the professor, who was lecturing about the fun of grammar.

  • while = sub-ordinating conjunction which introduces dependent clause
  • I = first person singular nominative pronoun; subject of dependent clause
  • waited = verb of dependent clause; past indicative singular
  • for = preposition introducing phrase modifying “waited” by explaining what was being waited for
  • the = article modifying bell
  • bell = noun; object of “for”
  • to ring = complementary infinitive of “waited”
  • I = first person singular nominative pronoun; subject of main verb
  • indulged = main verb; past singular
  • in = preposition introducing phrase that modifies the verb “engaged” by explaining what was being engaged in
  • seriously = adverb modifying “annoyed”
  • annoyed = adjective modifying “grumbling”; past participle of the verb “to annoy”
  • grumbling = noun / gerund of “to grumble”; object of the preposition “in”
  • at = preposition
  • the = article modifying “delusions”
  • delusions = noun; object of “at”
  • of = preposition introducing phrase that modifies “delusions” by explaining to whom they belonged
  • the = article modifying “professor”
  • professor = noun; object of “of,” antecedent of “who”
  • who = relative pronoun; subject of “was lecturing”; introduces clause modifying “professor” by supplying further information about him/her
  • was lecturing = main verb. Alternatively, you could think of “was” as the main verb, and “lecturing” as a present participle serving as the predicate adjective of “was.”
  • about = preposition; introduces phrase modifying the verb “was lecturing” by explaining what the lecture was about
  • the = article modifying “fun”
  • fun = noun; object of “about”
  • of = preposition introducing phrase that modifies “fun” by explaining what was fun
  • grammar = noun; object of “of”