Has your word processing program ever advised you to reconsider a sentence you just wrote? Have you ever sat and puzzled over it in frustration, wondering what it was so upset about?
Maybe your sentence wasnât really a sentence, after all. But how can you tell? What sets apart a real, honest-to-goodness sentence from a phrase or a fragment?
Well, you came to the right place for a simple, no-nonsense explanation.
Every sentence must have a subject, as well as a verb which tells what the subject is doing or being. It must express a complete thought, however brief. If you donât have those ingredients, then you donât have a sentence.
âNounâ is the technical term for words that name something, most often a person, a place, or a thing. For example, âwoman,â âlake,â and âcarâ are all nouns. âWomanâ is the English name for a female human, while âlakeâ names a medium-sized body of non-flowing water and âcarâ names a type of vehicle. Other, less tangible things can also be nouns, such as emotions or ideas.
Every sentence must be about something or, to put it another way, it must have a subject. That subject has to be a noun. For example, take the sentence âThe ball is green.â This sentence is about a ball. âBallâ is a name (noun) for a round object. While âgreenâ is also a name (noun), it is not what the sentence is about so it cannot function as the subject of this sentence. Of course, it certainly could form the subject of a different sentence, such as âGreen is my favorite color.â
So, to have a sentence, there must be a naming word (noun) that lets the reader know what the sentence is about.
Just sticking in a noun doesnât make a string of words into a sentence, no matter how long the string of words becomes. âIs greenâ doesnât become a sentence even though it contains the noun âgreen,â because it doesnât tell you what is green. Clearly, this is a fragmentary thought, and thatâs why such phrases are labeled âfragments.â Nor does it help to pile on more words. âIs lovely, pale, luminescent lime greenâ does not magically transform this into a sentence. There is still no clue as to what itâs talking about.
Iâll throw in one other tidbit about nouns, just for free, though it has nothing to do with determining whether or not you have a complete sentence as opposed to a fragment. But I find that people frequently have trouble with this next concept.
There are common nouns and proper nouns. Common nouns are, as might be expected, ordinary naming words, usually somewhat generic. All my sentence examples above use generic, common nouns: woman, lake, car, ball, green. They can refer, at least potentially, to any woman, any lake, any car.
Proper nouns, on the other hand, are the specific names given to only one thing. Not just any woman, but one specific woman: Hilary Clinton, for example. Not just any lake, but the one named Lake Tahoe. Not just any car, but your neighborâs new Camaro.
Notice that proper nouns always get capitalized, while common nouns do not. Usually this is fairly obvious, but once in awhile it can get tricky. For instance, âmotherâ is a common noun because it can potentially be naming anybodyâs mom. But if you start talking about your own mom and using the word in the sense that itâs the name you call her, then the word magically transforms into the proper noun âMother,â because now itâs the specific name of one specific person. Note that this only happens if you start using it as if it was her name. If you say, âI went to town with my mother,â youâre describing who she is (my mother) rather than naming her (Mom).
Okay, so there must be a subject in every sentence, a naming word (noun) that lets the reader know what or who the sentence is about. Letâs go on to the other essential ingredient of a sentence: the verb.
Verbs are action words or words that describe a state of being. Verbs tell what the subject is doing or being. Again, there could potentially be several verbs in a sentence, but there has to be at least one that tells about the subject.
In our sample sentence, âThe ball is green,â weâve already established that itâs talking about the ball. Thatâs the subject. Now, thereâs no action going on in the sentence, but thereâs still a verb. Itâs a âstate-of-beingâ verb, the little word âis.â   What happens if we leave it out? âThe ball green.â Sounds like someone who canât speak English well, like what we imagine a caveman might say, with a few grunts thrown in for good measure.
âThe pitcher threw the ballâ has an action verb, âthrew.â It tells what the subject (pitcher) did.
Sentences can be extremely simple, consisting of little more than a subject and a verb, and yet still convey a complete thought. âThe child ranâ or âMary duckedâ or âBob typedâ are all examples of complete sentences. Each is a complete (though certainly not elaborate) thought. Each contains a noun that tells who or what the sentence is talking about, and each contains a verb that tells what the subject did.
There is nothing wrong with simple sentences like these, and often they are the best sort of sentence to use when you want to express quick, forceful ideas or actions. If you use nothing else in your writing, however, it will soon become tedious. It may also make you sound like youâre about six years old.
Most people write longer sentences, and this is where they can get confused about whether they have a true sentence or only a fragment. Many times there is the belief that if you just add more words, your fragment will be transformed into a complete thought. But âfragmentâ doesnât mean âtoo short,â at least not in this case. It means ânot complete.â
Theoretically, you could write a fragment so long it took up an entire paragraphâor an entire pageâwithout ever sticking in a subject or a verb that related to it. This is one reason Iâve used such short sentences in my examples earlier. âMary duckedâ is a complete sentence. You donât need to be wordy to be correct. Of course, it also makes the concept of subject/verb easier to see and understand, since nearly everything else has been left out of these sentences.
Letâs finish up with a few longer examples. âAs she came out the back door, Mary ducked under the washing hanging up on the clothesline to dry in the bright sun and hot desert wind.â Obviously, this paints a clearer picture of the situation than the simple sentence, âMary ducked.â But it is not any more complete, grammatically speaking. Notice that the sentence, stripped of its descriptive verbiage, is still about Mary and what she did (duck).
âAfter coming home from school, ran out in the back yard and began digging frantically in the sandbox.â After reading this, you ought to get a sense that somethingâs missing. And what is missing is the subject. Who came home, ran outside, and dug up the sandbox? Well, we donât know. This makes the rest of the words fairly meaningless, as we have no idea who itâs talking about.
You have to have a subject for every sentence. Just having nouns isnât enough.  In the example above, âhome,â âschool,â âback yard,â and âsandboxâ are all nouns (names of things or places), but none of them tell who or what the sentence is about.
âHis fingers pounding the keyboard, Bob madly as he tried to finish his blog.â Again, something is decidedly missing. What did Bob (the subject of this sentence) do? We have no idea (although we could probably guess from the context in this instance that he was typing). In every sentence, you must have a verb that describes what the subject did.
And please note that just having a verb, or even several, will not do the trick. In the sentence above, âpoundingâ and âtriedâ are both verbs, but neither tells specifically what Bob is doing. Your verb has to tell something about the subjectâs action, feeling, or even simply its existence.
Grammar can be a complicated subject, but most of us can get by just fine in our everyday lives with only a few simple grammar rules. You donât always have to write in complete sentences, but itâs helpful to know when you are and when you arenât so you donât end up with fragments by mistake. Using complete sentences will make your writing more easily understandable by your readers, and since communication is the point of writing, thatâs a good thing.