What with all the rules and exceptions to the rules they are obliged to memorize in English courses from first grade through college, students often fail to learn one fundamental rule of grammar: You can usually hear the difference.
For instance, every student knows how to pronounce the word subject. But what if I tell him that I mean the verb, not the noun? He knows how to pronounce that, too, for he knows that the verb subJECT sounds different from the noun SUBject. (for example: Teachers subJECT their students to grammar tests when the SUBject is English.) The same difference distinguishes the verb susPECT from the noun SUSpect, and the verb obJECT from the noun OBject.
Every student distinguishes between the noun and verb forms of these words when speaking. But ask him to tell you which syllables of these words receive the stress, or accent, and the invariable response is that he doesnŐt know anything about accents. But he does make a distinction between the noun and verb forms of the word subject when speaking and, at gunpoint, will concede that he hears the difference in sound.
The difference is one of stress. In the noun form of the word subject, the stress, or accent, falls on the first syllable: SUB-ject. In the verb form, the emphasis is on the second syllable: sub-JECT.
Having learned that the difference in sound between the verb and noun forms of the words subject, suspect, and object is one of stress, the student can use this knowledge to avoid the misspellings that frequently result when a student adds -ed or -ing to a two-syllable verb. What is the difference in sound between the verbs suffer, offer and conquer and the verbs refer, occur and concur? Which ones double the final consonant before adding -ed or -ing? Which ones don't? What makes conquer sound different from concur?
In the verbs suffer, offer and conquer, the stress falls on the first syllable: SUF-fer, OF-fer, CON-quer. In the verbs refer, occur and concur, the accent falls on the second syllable: re-FER, oc-CUR, con-CUR.
Now examine this sentence: The counselor offered advice to the student who had been referred to him. The ending -ed has been added to the verb offer without doubling the r, while the final r in refer has been doubled before the addition of -ed. Offer, suffer and conquer do not require the doubling of their final consonants before the addition of -ed or -ing: offered, suffered, conquered. Refer, occur, and concur do: referred, occurred, concurred.
It doesn't take a genius to infer (accent on the second syllable, double the r before adding -ed: inferred) that two-syllable verbs with the accent on the first syllable do not need to double their last consonant before adding -ed or -ing, and that two-syllable verbs with the accent on the second syllable do. Armed with this inference, the student needs no rules to spell these words correctly. He need only know how to pronounce them.
The Long and the Short of It
By hearing the difference in sound, the student can also know when to double the final consonant before adding -ed or -ing to a single-syllable verb. Take the verbs mat, pet, pit, hop and pun and the verbs mate, seat, bide, hope and prune. What is the major difference between these two sets of single-syllable verbs? Which set doubles the last consonant before adding -ed or -ing? Which set doesn't? How do you describe the difference in sound between the words mat and mate?
The verbs mat, pet, pit, hop and pun all contain short vowels. The verbs mate, seat, bide, hope and prune all contain long vowels. (The vowels you pronounce when you recite the alphabet are long vowels: A, E, I, O, U.) Mat, pet, pit, hop and pun all double their final consonant before adding -ed or -ing: matted, petted, pitted, hopped, punned. Mate, seat, bide, hope and prune do not: mated, seated, bided, hoped, pruned.
One-syllable verbs with short vowels double the final consonant before adding -ed or -ing. One-syllable verbs with long vowels do not. Again, the student need only know what he already knows -- how to pronounce these words -- to be able to spell them correctly when adding -ed or -ing.
The Case for Commas
An ear for grammar can help the student in punctuation as well as in spelling. For instance, if I said, "I went to visit my sister who lives in Dallas," you would know two things about me: 1) I went to visit my sister, and 2) my sister lives in Dallas. But you could, if you wanted to, infer a third: I have more than one sister. If, on the other hand, I said, "I went to visit my sister, who lives in Dallas," you would, if you thought about it, be inclined to conclude that I have only one sister.
The only difference between these two sentences is the comma which follows the word sister in the second. And yet, that one little comma -- corresponding to the pause I would take in speech -- is capable of giving you an idea of the size of my family! For, in that first sentence, the one without the comma, that clause "who lives in Dallas" tells you not so much where my sister lives as which sister I'm talking about. Given the fact that I feel obliged to distinguish sisters, I must have more than one; and the information I have provided in the clause is essential if you are to know which sister I'm speaking of.
However, in the second sentence, the one with the comma, the clause "who lives in Dallas" is delivered, after a pause, as additional, unessential information, telling you where my sister lives. Since I have made no attempt to distinguish sisters, you would be justified in suspecting that I have only one.
When using sentences with clauses like these, the student need only determine if the information in the clause is essential or unessential. If essential, there would be no pause in speech, no comma in writing. If unessential, a comma is required to connect the clause to the rest of the sentence.
If I were to ask, "Do you want coffee or tea?" I would most likely be answered with "yes" or "no." If yes, I would then be obliged to ask a second question to determine which of the two drinks was preferred. On the other hand, if I asked, "Do you want coffee, or tea?" the most likely answer would be "coffee" or "tea," or "neither."
Like the comma after the word sister in the sentence above, that little pause after the word coffee in the second question is charged with meaning. It indicates that the person questioned is expected to select between the two beverages.
Here again, the difference in meaning can be heard. To punctuate these questions correctly, the student need only determine which meaning he intends, which answer he is soliciting.
Although students incompetent in grammar may be inclined to think punctuation strictly a matter of personal preference, it is clear from the example of the two sets of sentences above that the placement of commas is not an arbitrary matter. A change in punctuation corresponded to a change in sound, which indicated a change in meaning. The difference could be heard. Commas, then, are signals, not ornaments.
One shortcoming of rules of grammar is that they require a familiarity with the vocabulary of grammar. If a student doesn't know what gerunds, participles and prepositions are, he isn't going to understand rules referring to them. Another shortcoming of grammar rules is that they're often forgotten more easily than they are learned.
But by hearing the difference in sound and meaning made by the position of accents, the quality of vowels, and the placement of punctuation, the student can dispense with the memorization of rules. He will not only spell and punctuate with greater accuracy; he will also discover that grammar is a matter of common sense and not just a set of arbitrary rules.