A few grammar definitions
(By Ross Collins, professor of communication, North Dakota State University, Fargo)
And I do mean a few. These amplify the rules from the main lecture, in that order. And, yes, I will quickly agree with you: some brilliant writers break some rules and still produce writing far better than anything I can serve up. But writing is like art; first learn the principles, then learn when you can skip them.
(More information: SparkNotes.)
A sentence is basically a way of telling folks what's going on: who is doing what (and possibly to whom).
The eight parts of speech:
Nouns, pronouns, verbs, adjectives, adverbs, prepositions, conjunctions and interjections.
Nouns.
A noun is used to name a person, place or thing. It is one of the eight parts of speech (see above).
This is the big heavyweight in the sentence. Without a subject (stated or implied), the whole flurry of words after means just about nothing. For example, I could say "wrote the syllabus." But you would respond, "So what? Who's doing that writing?" A big important noun would make it all clear: "Professor Ross wrote the syllabus."
Examples from a nice summer day (as I'm writing this in January):
Ross threw the ball.
The ball is green.
The dog caught the ball.
They played in the park.
Verbs.
A verb describes action or state of being. In the example above, verbs are is, caught, and played.
Mass media writers emphasize verbs, because verbs describe action. If media writing is about people doing things, well, strong verbs pull possibly sullen nouns off the couch and into the game. This is why we try to avoid the being verb, "to be." (Is, are, was were, will be.) In the example above, "The ball is green" merely demonstrates a state of being. States of being don't move around much. But we could improve that verb, by saying "The ball traced a streak of luminous green as it skittered across the pavement." Now that ball goes somewhere.
Adjectives.
An adjective modifies a noun (and an adverb modifies a verb). That means it alters the basic meaning of a noun. Example:
The ball.
The red ball.
The over-inflated red beach ball.
Each adjective adds description to the basic noun.
Mass media writers tend to avoid adjectives, as a strong noun standing alone produces more readable copy. Particularly we avoid that poor, tired, overused adjective very. Very adds nothing to a noun; in fact, it detracts from its power:
The ball.
The red ball.
The very red ball.
Do you think the ball seems a lot more red now that I've added "very?" Overuse of this adjective is a dead giveaway of amateur writing.
Vowels and consonants.
I suppose I don't have to tell you what these are, as we learned them in first grade. But think about it; can you define a vowel without just giving the examples from grade school? "A, e, i, o u, and sometimes y." The rest are consonants. So what are they, then? Now we have to think. In fact, the formal definition of vowels are sounds produced without restricting air pressure through the lips and tongue. Consonants restrict air to produce a harder sound.
We need both vowels and consonants to form a language, any language. All words in English contain one or more vowels, without which we would not be able to pronounce words. The study of this is part of phonetics.
Clauses.
Words that express a complete thought within a sentence. To do that, you need a subject and a verb. "As they frolicked in the park, Ross threw the ball to the dog." "Ross threw the ball" is a clause. It contains a complete thought. But it is part of a compound sentence. Note the subordinate clause, "As they frolicked in the park."
Of course, a subordinate clause is just part of a thought, so can't stand alone.
If a phrase (group of words) does not contain a subject or verb, it is a sentence fragment. "Threw the ball" contains no subject (noun), and so is incorrect grammar.
Prepositions.
A preposition forms a link to help us further describe the relationship of nouns, pronouns or phrases to the rest of the sentence. Usually we are trying to talk about where something is, physically, or in time. The noun whose place we are trying to describe is called the object of the preposition.
Prepositions, then, are those little yet oh-so-essential words that help you get specific: above, around, at, below, between, for, inside, over, until up, without, etc.
Note the preposition, object, and other words that may modify it together are called a preppositional phrase.
The iPod Touch is on the desk.
He stashed a bottle of Red Bull inside the cabinet.
The student stowed his backpack during the exam.
Learn more about prepositions.
Compound words.
Devilishly difficult, because counter-intuitive (or is it counterintuitive?). Why is house key still two words, but keyhole one? Why is school teacher two words, but schoolroom one? The answer: changes forced by common usage over the years. Familiar phrases tend to meld as time goes on; web site to website, per cent to percent. Probably health care is on the way to healthcare. Many advertisers who like this trend have squeezed those words already into the same space. But we have no grammatical rule to help us out, beyond dictates of the AP Stylebook.
When in doubt, it's probably better to keep the words separate. But here is a list of those we have generally compounded.
Direct/Indirect Objects.
A noun (or pronoun) that receives the action of the verb.
In the now-tired example above, "Ross threw the ball," ball is the direct object. It answers the question, threw who? Or what?
You can put it into passive voice, "The ball was thrown by Ross," and it still makes sense (though we try to avoid passive voice in media style writing). This means ball is indeed a direct object.
If you already have a direct object, feel free to add an indirect object. "Ross threw Rover a ball." The answer to the question "to who or to whom" is "Rover," the direct object.
Learn more about direct/indirect objects.