Auxiliary Verbs or Helping

Auxiliary Verbs or Helping

Helping verbs or auxiliary verbssuch as will, shall, may, might, can, could, must, ought to, should, would, used to, need are used in conjunction with main verbsto express shades of time and mood. The combination of helping verbs with main verbs creates what are called verb phrases or verb strings. In the following sentence, "will have been" are helping or auxiliary verbs and "studying" is the main verb; the whole verb string is underlined:

• As of next August, I will have been studyingchemistry for ten years.

Students should remember that adverbs and contracted forms are not, technically, part of the verb. In the sentence, "He has already started." the adverb alreadymodifies the verb, but it is not really part of the verb. The same is true of the 'ntin "He hasn't started yet" (the adverb not, represented by the contracted n't, is not part of the verb, has started).
Shall, will and forms of have, do and becombine with main verbs to indicate time and voice. As auxiliaries, the verbs be, have and docan change form to indicate changes in subject and time.

• I shall go now.
• He had won the election.
• They didwrite that novel together.
• I am going now.
• He was winning the election.
• They have beenwriting that novel for a long time.

Uses of Shall and Will and Should In England, shall is used to express the simple future for first person I and we, as in "Shall we meet by the river?" Willwould be used in the simple future for all other persons. Using willin the first person would express determination on the part of the speaker, as in "We will finish this project by tonight, by golly!" Using shallin second and third persons would indicate some kind of promise about the subject, as in "This shall be revealed to you in good time." This usage is certainly acceptable in the U.S., although shallis used far less frequently. The distinction between the two is often obscured by the contraction 'll,which is the same for both verbs. In the United States, we seldom use shallfor anything other than polite questions (suggesting an element of permission) in the first-person: "Shall we go now?" "Shall I call a doctor for you?" (In the second sentence, many writers would use shouldinstead, although shouldis somewhat more tentative than shall.) In the U.S., to express the future tense, the verb willis used in all other cases. Shallis often used in formal situations (legal or legalistic documents, minutes to meetings, etc.) to express obligation, even with third-person and second-person constructions: The board of directors shall be responsible for payment to stockholders. The college president shall report financial shortfalls to the executive director each semester." Shouldis usually replaced, nowadays, by would. It is still used, however, to mean "ought to" as in You really shouldn't do that. If you think that was amazing, you should have seen it last night. In British English and very formal American English, one is apt to hear or read shouldwith the first-person pronouns in expressions of liking such as "I should prefer iced tea" and in tentative expressions of opinion such as I should imagine they'll vote Conservative. I should have thought so. (The New Fowler's Modern English Usageedited by R.W. Burchfield. Clarendon Press: Oxford, England. 1996. Used with the permission of Oxford University Press. Examples our own.)

Uses of Do, Does and Did In the simple present tense, dowill function as an auxiliary to express the negative and to ask questions. (Does, however, is substituted for third-person, singular subjects in the present tense. The past tense didworks with all persons, singular and plural.) I don't study at night. She doesn't work here anymore. Do you attend this school? Does he work here? These verbs also work as "short answers," with the main verb omitted. Does she work here? No, she doesn't work here. With "yes-no" questions, the form of dogoes in front of the subject and the main verb comes after the subject: Didyour grandmother knowTruman? Do wildflowers growin your back yard? Forms of do are useful in expressing similarity and differences in conjunction with so and neither. My wife hates spinach and so does my son. My wife doesn't like spinach; neither do I. Dois also helpful because it means you don't have to repeat the verb: Larry excelled in language studies; so didhis brother. Raoul studies as hard as his sister does. The so-called emphatic dohas many uses in English. To add emphasis to an entire sentence: "He doeslike spinach. He really does!" To add emphasis to an imperative: "Docome in." (actually softens the command) To add emphasis to a frequency adverb: "He never didunderstand his father." "She always doesmanage to hurt her mother's feelings." To contradict a negative statement: "You didn't do your homework, did you?" "Oh, but I didfinish it." To ask a clarifying question about a previous negative statement: "Ridwell didn't take the tools." "Then who didtake the tools?" To indicate a strong concession: "Although the Clintons denied any wrong-doing, they did return some of the gifts." In the absence of other modal auxiliaries, a form of dois used in question and negative constructions known as the get passive: DidRinaldo get selected by the committee? The audience didn't get riled up by the politician. Based on descriptions in Grammar Dimensions: Form, Meaning, and Use2nd Ed. by Jan Frodesen and Janet Eyring. Heinle & Heinle: Boston. 1997. Examples our own.

Uses of Have, Has and Had Forms of the verb to have are used to create tenses known as the present perfect and past perfect. The perfect tenses indicate that something has happened in the past; the present perfect indicating that something happened and might be continuing to happen, the past perfect indicating that something happened prior to something else happening. (That sounds worse than it really is!) See the section on Verb Tenses in the Active Voicefor further explanation; also review material in the Directory of English Tenses. To have is also in combination with other modal verbs to express probability and possibility in the past. As an affirmative statement, to havecan express how certain you are that something happened (when combined with an appropriate modal + have+ a past participle): "Georgia must have left already." "Clinton might have known about the gifts." "They may have voted already." As a negative statement, a modal is combined with not + have+ a past participle to express how certain you are that something did not happen: "Clinton might not have known about the gifts." "I may not have been there at the time of the crime." To ask about possibility or probability in the past, a modal is combined with the subject + have+ past participle: "Could Clinton have known about the gifts?" For short answers, a modal is combined with have: "Did Clinton know about this?" "I don't know. He may have." "The evidence is pretty positive. He must have." To have (sometimes combined with to get) is used to express a logical inference: It's been raining all week; the basement has to be flooded by now. He hit his head on the doorway. He has got to be over seven feet tall! Haveis often combined with an infinitive to form an auxiliary whose meaning is similar to "must." I have to have a car like that! She has to pay her own tuition at college. He has to have been the first student to try that. Based on the analysis in Grammar Dimensions: Form, Meaning, and Use2nd Ed. by Jan Frodesen and Janet Eyring. Heinle & Heinle: Boston. 1997. Examples our own.

Modal Auxiliaries

Other helping verbs, called modal auxiliaries or modals, such as can, could, may, might, must, ought to, shall, should, will, and would, do not change form for different subjects. For instance, try substituting any of these modal auxiliaries for canwith any of the subjects listed below.

I you (singular) he we you (plural) they	can write well.

There is also a separate section on the Modal Auxiliaries, which divides these verbs into their various meanings of necessity, advice, ability, expectation, permission, possibility, etc., and provides sample sentences in various tenses. See the section on Conditional Verb Formsfor help with the modal auxiliary would. The shades of meaning among modal auxiliaries are multifarious and complex. Most English-as-a-Second-Language textbooks will contain at least one chapter on their usage. For more advanced students, A University Grammar of English, by Randolph Quirk and Sidney Greenbaum, contains an excellent, extensive analysis of modal auxiliaries.
The analysis of Modal Auxiliariesis based on a similar analysis in The Scott, Foresman Handbook for Writersby Maxine Hairston and John J. Ruszkiewicz. 4th ed. HarperCollins: New York. 1996. The description of helping verbs on this page is based on The Little, Brown Handbookby H. Ramsay Fowler and Jane E. Aaron, & Kay Limburg. 6th ed. HarperCollins: New York. 1995. By permission of Addison-Wesley Educational Publishers Inc. Examples in all cases are our own.

Uses of Can and Could The modal auxiliary can is used to express ability (in the sense of being able to do something or knowing how to do something): He can speak Spanish but he can't write it very well. to expression permission (in the sense of being allowed or permitted to do something): Can I talk to my friends in the library waiting room? (Note that canis less formal than may. Also, some writers will object to the use of canin this context.) to express theoretical possibility: American automobile makers can make better cars if they think there's a profit in it. The modal auxiliary could is used to express an ability in the past: I could always beat you at tennis when we were kids. to express past or future permission: Could I bury my cat in your back yard? to express present possibility: We could always spend the afternoon just sitting around talking. to express possibility or ability in contingent circumstances: If he studied harder, he could pass this course. In expressing ability, can and couldfrequently also imply willingness: Can you help me with my homework?

Can versus May Whether the auxiliary verb cancan be used to express permission or not — "Can I leave the room now?" ["I don't know if you can, but you may."] — depends on the level of formality of your text or situation. As Theodore Bernstein puts it in The Careful Writer,"a writer who is attentive to the proprieties will preserve the traditional distinction: canfor ability or power to do something, mayfor permission to do it. The question is at what level can you safely ignore the "proprieties." Merriam-Webster's Dictionary, tenth edition, says the battle is over and can can be used in virtually any situation to express or ask for permission. Most authorities, however, recommend a stricter adherence to the distinction, at least in formal situations. Authority: The Careful Writer by Theodore Bernstein. The Free Press: New York. 1998. p. 87.

Uses of May and Might Two of the more troublesome modal auxiliaries are may and might. When used in the context of granting or seeking permission, mightis the past tense of may. Mightis considerably more tentative than may. May I leave class early? If I've finished all my work and I'm really quiet, might I leave early? In the context of expressing possibility, may and mightare interchangeable present and future forms and might + have+ past participle is the past form: She might be my advisor next semester. She may be my advisor next semester. She might have advised me not to take biology. Avoid confusing the sense of possibility in maywith the implication of might,that a hypothetical situation has not in fact occurred. For instance, let's say there's been a helicopter crash at the airport. In his initial report, before all the facts are gathered, a newscaster could say that the pilot "mayhave been injured." After we discover that the pilot is in fact all right, the newscaster can now say that the pilot "mighthave been injured" because it is a hypothetical situation that has not occurred. Another example: a body had been identified after much work by a detective. It was reported that "without this painstaking work, the body mayhave remained unidentified." Since the body was, in fact, identified, mightis clearly called for.

Uses of Will and Would In certain contexts, will and would are virtually interchangeable, but there are differences. Notice that the contracted form 'll is very frequently used for will. Willcan be used to express willingness: I'll wash the dishes if you dry. We're going to the movies. Will you join us? It can also express intention (especially in the first person): I'll do my exercises later on. and prediction: specific: The meeting will be over soon. timeless: Humidity will ruin my hairdo. habitual: The river will overflow its banks every spring. Wouldcan also be used to express willingness: Would you please take off your hat? It can also express insistence (rather rare, and with a strong stress on the word "would"): Now you've ruined everything. You would act that way. and characteristic activity: customary: After work, he would walk to his home in West Hartford. typical (casual): She would cause the whole family to be late, every time. In a main clause, wouldcan express a hypothetical meaning: My cocker spaniel would weigh a ton if I let her eat what she wants. Finally, wouldcan express a sense of probability: I hear a whistle. That would be the five o'clock train.

Uses of Used to The auxiliary verb construction used tois used to express an action that took place in the past, perhaps customarily, but now that action no longer customarily takes place: We used to take long vacation trips with the whole family. The spelling of this verb is a problem for some people because the "-ed" ending quite naturally disappears in speaking: "We yoostoo take long trips." But it ought not to disappear in writing. There are exceptions, though. When the auxiliary is combined with another auxiliary, did,the past tense is carried by the new auxiliary and the "-ed" ending is dropped. This will often happen in the interrogative: Didn't you use to go jogging every morning before breakfast? It didn't use to be that way. Used tocan also be used to convey the sense of being accustomed to or familiar with something: The tire factory down the road really stinks, but we're used to it by now. I like these old sneakers; I'm used to them. Used tois best reserved for colloquial usage; it has no place in formal or academic text.

ที่มา : http://grammar.ccc.commnet.edu/grammar/auxiliary.htm