In the [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط], a modal verb is a type of [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط]. The key way to identify a modal verb is by its [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] (they have neither [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] nor [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط]). In addition, modal verbs do not take the inflection -s or -es in the third person singular, unlike other verbs.
The modal verbs in English are as follows, paired as present and [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] forms.
Note that use of the preterite forms does not necessarily refer to past time.
The following have also been categorized by some as modal verbs:[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط]:p. 33;[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط]
Note that dare and need are much more commonly used as non-modal verbs, taking -s or -es in the third person singular and having an infinitive and past and present participles. Further, some authors[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط]:pp.3,8 do not mention had better and explicitly reject ought (to) on the grounds that the main verb infinitive is required to include the particle to.
The following are not modal verbs although they have some similar characteristics:
Shall is used in many of the same senses as will, though not all dialects use shall. In prescriptive English usage, shall in the first person, singular or plural, indicates mere futurity, but in other persons shows an order, command or prophecy: "Cinderella, you shall go to the ball!" Likewise, will generally indicates futurity in the second and third persons but willingness/determination in the first person.
In dialects that seldom use shall, will has a number of different uses[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط]:pp.86-97;[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط]:pp. 21, 47-48:
It can express aspect alone, without implying futurity: In "He will make mistakes, won't he?", the reference is to a tendency in the past, present, and future and as such expresses habitual aspect. It can express probability in the present time, as in "That will be John at the door", or obligation, as in "You will do it right now". It can express both intention and futurity, as in "I will do it." It can express futurity: "The sun will die in a few billion years."
Shall is also used in legal and engineering language to write firm laws and specifications as in these examples: "Those convicted of violating this law shall be imprisoned for a term of not less than three years nor more than seven years," and "The electronics noembly shall be able to operate within its specifications over a temperature range of 0 degrees Celsius to 70 degrees Celsius." In both cases, in accordance with prescriptive usage, shall is used in the third person to express determination on the part of the speaker.
Should is commonly used, even in dialects where shall is not. The negation is "should not" (or the [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] "shouldn't").
Should can describe an ideal behaviour or occurrence and imparts a [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] meaning to the sentence; for example, "You should never lie" means roughly, "If you always behaved perfectly, you would never lie", so obligation. The sentence "If this works, you should not feel a thing" means roughly, "I hope this will work. If it does, you will not feel a thing", so probability is being expressed. In dialects that use shall commonly, however, this restriction does not apply; for example, a speaker of such a dialect might say, "If I failed that test, I think I should cry," meaning the same thing as, "If I failed that test, I think I would cry"; here the use of should is for conditionality.
In some dialects, it is common to replace the [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] with the modal auxiliary should: "It is important that the law should be passed" (where other dialects would say, "It is important that the law be pnoed"); likewise "If it should happen, we are prepared for it" or "Should it happen, we are prepared for it" (where early Modern English would say, "If it happen, we are prepared for it," and many dialects of today would say, "If it happens, we are prepared for it" or the subjunctive "If it were to happen, we would be prepared for it.").
The [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] form of would is 'd as in "I'd go if I could". The negation is either would not or wouldn't.
As indicated above, would can be used for the conditional mood in main clauses: "I would go if I could".
Would can be used in some forms that are viewed as more formal or polite: for example, "I would like a glass of water" compared with "I want a glass of water"; and "Would you get me a glass of water?" compared with the bare "Get me a glno of water."
Would can also be used for the [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] in past time. In the sentence "Back then, I would eat early and would walk to school...." "would" signifies not the [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط], but rather, repeated past actions in the imperfective [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] (specifically, habitual aspect)[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط][ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] and one must use care when translating to other languages.
Furthermore, would can be used to shift the time of perspective of a future event from the present to the past: "In 1982 I knew that in 1986 I would graduate from college."
The meaning of the negated "would" form depends on the particular usage of "would". In its conditional usage, the main verb is negated: "I would not go even if I could" means "I would not-go..." = "I would refrain from going...." However, in the future-of-the-past form, "In 1982 I knew that I would not graduate in 1986" means "...I not-would graduate..." = "...It is not that I would graduate...." Likewise, in the past habitual form, "Back then I would not eat early" does not mean "...I would not-eat early" = "...I would fast early" but rather means "...I not-would eat early" = "...it is not that I would eat early...." In the latter two examples either the modal or the entire verb phrase is being negated.
It is also used to make past predictions or a prediction about a possible situation:
past: Sarah worked all night. She would be tired the next day.
possible: Shall we go to Keri Keri for Easter? That would be nice.
May and might
May and might do not have common negative contractions (equivalents to shan't, won't, can't, couldn't etc.), although mightn't can occur in asking questions. ("Mightn't I come in if I took my muddy boots off?" as a reply to "Don't come in here! You'll get the floor dirty!")
Both forms can be used to express a present time possibility or uncertainty ("That may be."). Might and could can also be used in this sense with no past time meaning. Might and may would carry almost the same meaning in "John is not in the office today, and he could be sick", although may conveys less hesitance (a somewhat higher probability) than do might and could.
When used in the perfect aspect, "may have" is used to indicate a lack of knowledge about events in the past, and "might have" is used for possibilities that did not occur but could have in other circumstances, in a similar way to other [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط].
"She may have eaten cake, it was there." "She might have eaten cake, if it wasn't a lie".
May is also used to express irrelevance in spite of certain or likely truth: "He may be taller than I am, but he is certainly not stronger" may mean roughly, "While it is true that he is taller than I am, that does not make a difference, as he is certainly not stronger." (However, it may also mean, "I am not sure whether he is taller than I am, but I am sure that he is not stronger.") This is the meaning in the phrase "Be that as it may." Might can be used in this sense as well.
May or might can be used in the first person to express that future actions are being considered. "I may/might go to the mall later" means that the speaker is thinking about going to the mall; as such it means the same thing as maybe will.
May and might can indicate permission and mild permission respectively: "You may go now", "You might go now if you feel like it." May or might can be used in a question to ask for permission. One who is saying "May I use your phone?” is asking for permission to use the phone of the person being spoken to. "Can" or "could" can be used instead, although formal American English prefers "may". In both cases the preterite form is viewed as more hesitant or polite.
The meaning of the negated "may" or "might" form depends on the usage of the modal. When possibility is indicated, the main verb is negated: "That may/might not be" means "That may/might not-be" = "That may fail to be true." But when permission is being expressed, the modal or the entire verb phrase is negated: "You may not go now" does not mean "You may not-go now" = "You may stay now", but rather means "You not-may go now" = "You are forbidden to go now." Sometimes, though, the main verb is negated by putting stress on both "not" and the main verb: "You may go or not go, whichever you wish."
Can and could
The negation of can is the single word "cannot", occasionally written as two words "can not"[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] or the contraction "can't". The negation of could is "could not", or "couldn't".
Can is used to express ability. "I can speak English" means "I am able to speak English", or "I know how to speak English".
It is also used to express that some state of affairs is possible, without referring to the ability of a person to do something: "There can be a very strong rivalry between siblings" can have the same meaning as "There is sometimes a very strong rivalry between siblings".
Cannot and can't can be used to express beliefs about situations: "He cannot have left already; why would he want to get there so early?" expresses with less certainty the same proposition as "He has not left already" does.
Both can and could can be used to make requests: "Can you pass me the cheese?" means "Please pno me the cheese". Could can be used in the same way, and might be considered more polite.
Informally, can is frequently used to mean may in the sense of permission: "You can go now."
The form could can indicate either ability in the past (= was able to) ("I could swim when I was five years old"), permission in the past (= was permitted to) ("My mother said that I could go swimming"), possibility in the present (=maybe) ("It could be raining now"), or conditionality in the present (= would be able to) ("I could do it if you would let me").
The negative forms virtually always negate the modal or entire verb phrase, and never just the main verb: "I cannot speak English" = "I am not able to speak English"; "You cannot go now" = "You are not allowed to go now"; "He could not do that" implying either permission or ability means "He was not allowed/able to do that." Rarely, the main verb is negated by putting stress on "not" and the main verb: "I could not do that, but I'm going to do it anyway."
Can is only used in a few situations in the perfect aspect:
With negative [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط]: "She can't have finished yet." (The speaker believes that she has not finished.)
Must has no corresponding preterite form. The negation is "must not" or "mustn't". An archaic variant is the word mote, as used in the expression "so mote it be".
Must and have to are used to express that something is obligatory ("He must leave"; "He has to leave"). Must can be used to express a prohibition such as "You must not smoke in here", or a resolution such as "I mustn't make that mistake again".
There is a distinction between "must" and "have to" in the negative forms: "must not" negates the main verb, while "do not have to" negates "have to". In the sentence "You must not go" = "You must not-go", it is being expressed that it is obligatory for the person being spoken to not go; whereas in the sentence "You do not have to go" it is being expressed that it is not obligatory for the person to go.
Must and have to can also be used to express strongly held beliefs (the [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط] use), such as "It must be here somewhere" or "It has to be here somewhere", with the same meaning as "I believe that it's very likely that it is here somewhere."
Ought to and had better
Ought to and had better are used to express an ideal behavior or occurrence or suggested obligation, in a similar way to should. The negations are, respectively, ought not to (or rarely, oughtn't to) and had better not. The "had" in "had better" can be contracted, such as "You'd better shut up." In informal American usage, the had in had better is sometimes omitted. The negative forms negate the main verb: "You ought not to do that" = "You ought to refrain from doing that"; "You'd better not do that" = "You'd better refrain from doing that."
In addition, ought to, like should, can be used to express relatively high probability, as in "It ought to rain today."
Dare and need
Dare and need are not commonly used as auxiliaries nowadays, but formerly they both were. Neither is used in affirmative declarative sentences. An example in an exclamation is "How dare he!", expressing willingness in the face of fear or contrary obligation. The interrogative form "Dare he do it?" or "Need he do it?" is equivalent to the non-auxiliary form "Does he dare to do it?" or "Does he need to do it?"; need, of course, expresses necessity. In a negative context "He dare not do it" is equivalent to "He does not dare to do it", while "He need not do it" is equivalent to "He does not need to do it". In both cases it is the modal or entire verb phrase, rather than the main verb, that is being negated.
However, in the sentence "He does not dare to lose weight" or "He needs to lose weight," dare or need is not being used as an auxiliary, as (1) it takes the full infinitive "to lose" as the head of the verb phrase rather than the bare infinitive "lose" that occurs in a phrase like "I can lose weight", and (2) the verb following it is conjugated in the third person singular.
Used to is used to express past states or past actions that were habitual but which are no longer. For example, "I used to go to college" suggests that the speaker no longer goes to college. Constructions negating the main verb exist in expressions such as "She used to not like me", or if the speaker is trying to avoid the [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط], "She used not to like me".
In Standard American English, although not the most formal style, used to can follow did not (or didn't), as in "She didn't use to like me". Here it is the entire verb form "used to like" that is being negated, to mean "It's not that she used to like me."
As an auxiliary, do is essentially a "dummy"; that is, it does not generally affect the meaning. It is used to form questions and negations when no other auxiliary is present: "Do you want to do it?", "I do not (don't) want to do it." This particular use of do, known as [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط], is attested from around 1400.
It is also sometimes used for emphasis: "I do understand your concern, but I do not think that will happen." Also, do sometimes acts as a [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط]: "I enjoy it, I really do [enjoy it], but I am not good at it." (Other auxiliaries do this as well: "I can do it, I really can [do it], it just takes me longer"; but it bears particular note that in the case of do, it is often used as a pro-verb when it would be absent if the verb were present.) Because it does not affect the meaning of its verb as regards the attitude of the speaker toward the action, it is not a modal auxiliary. In a sense, it indicates the lack of a modal auxiliary. (Do is also different in that it has a distinct third-person singular form, does, and in that its past tense, did, is used exactly as a past tense, not as a more general remote form).
Am/is/are/was/were going to is used in some of the same situations as is will: specifically, to indicate imminent futurity ("It's going to rain"), distant futurity ("The sun is going to die eventually"), intention ("I was going to do that, but I forgot"), or a combination of futurity and intentionality ("I'm going to do it tomorrow"). It always implies prospective aspect, combining the present (or past when used with was/were) focus in the main verb am/is/are/was/were going with the futurity of the second verb. Thus, for example, "It's going to rain" combines a present viewpoint of the situation with a description of the future. This feature is analogous to the retrospective aspect of the English present perfect have/has + VERB + -ed, in which past action is presented from the viewpoint of the present.
Am/is/are/was/were going to is not a modal because (1) it has an infinitive form to go, and (2) it requires a helping verb, which conjugates by person/number.
Have to is used in a similar way to must, as discussed above, except that have to is used either with an impersonal necessity (such as in "It has to be cloudy for it to rain") or a personal obligation ("I have to go to the dentist") while must is used primarily with personal obligations ("I must go to the dentist"). Have to can be used for an ongoing obligation, such as "he has to be careful". Have to is not a modal verb because (1) it has an infinitive form (to have [to]), and (2) it conjugates in the third person singular ("He has to do it").