Semi-modal

Semi-modals can behave grammatically either like lexical verbs or like core modal verbs.

need

obligationdutynecessityrequirement

• need [NP] - I need your help
• need to [VP] - The car needs to be washed
  • you need to sit downimperative
• need for [NP] to [VP] - I need for this to happen
• need [NP] to [VP] - I need this to happen
  • I need you to sit downimperative
• need [gerund-participle] - The car needs washing
• need [V3] - The car needs washed
• As a modal verb, with a bare infinitive; in negative polarity contexts, such as questions (“Need I say more?” “Need you have paid so much?”), with negative expressions such as not (“It need not happen today”; “No one need ever know”), and with similar constructions (“There need only be one”; “it need be signed only by the president”; “I need hardly explain it”). Need in this use does not have inflected forms, aside from the contraction needn’t.

used to

• Pasthabit
• The negative of used to is most typically didn’t use to (I didn’t use to like jazz). In more formal styles, used not to occurs (I used not to like jazz). The contracted form usedn’t to may occasionally occur, but is very rare
• The interrogative of used to has two forms; the more common form is with auxiliary did. (Did you used to like jazz) The alternative form involves subject-verb inversion (Used you to like jazz), and is very rare

ought to

dutycorrectnessprobability desirableideal

• Interrogative form (Ought we to call the police?)
• Negative form (*I ought not to go)
• Question tags (This picture ought to be hung somewhere, oughtn’t it?)
• Interrogatives, negatives and question tags with ought to are very rare; should is generally preferred instead (This picture ought to be hung somewhere, shouldn’t it?)

dare

todo

Modal Expressions

• ought to
• be tofuture
  • You are not to tell anyoneprohibition
  • She was to have met a gentleman friend at Southampton
  • They are to be married next month.
  • They are to stay here until I return.
  • They are not to be blamed.
  • How are they to get out of this mess?
  • I am to leave tomorrow.
  • I would drive you, were I to obtain a car.
• have todutyobligationnecessity
• hope to
• intend to
• long to
• agree to
• choose to
• consent to
• conspire to
• desire to
• expect to
• mean to
• offer to
• plan to
• propose to
• want to
• wish to
• yearn to
• aim to
• aspire to
• commit to
• decide to
• promise to
• resolve to
• swear to
• threaten to

Other modal expressions with be

• be meant tointended
• be supposed toobligationexpediencyintended
• be about tofuture
• be able toability
• be bound tounavoidableintendeddestinedfuture
• be due tofuture
• be likely to/thatprobability
• be obliged toobligation
• be going tofuture
• be best to
• be better to

had better

correctnessproprietyexpediency

• [subject] had better (not) [VP]
  • It’s five o’clock. I had better go now before the traffic gets too bad.
• `had (not) [subject] better [VP]
  • Had I better speak to Joan first before I send this form off? What do you think?

The same for had best