AuxiliariesThere are four verbs which are sometimes auxiliary verbs: be, do, get, and have. They are used mainly to add meaning to a main verb, for example by forming a continuous tense, a passive, a negative, or an interrogative. They are also used to add meaning to a clause, for example by helping to form question tags.Like other verbs, auxiliaries have tenses, some of which are formed with other auxiliaries. For example, in the clause She has been singing for two hours, the auxiliary be is used in the pattern AUX -ing, that is, been singing. However, the auxiliary be itself has a tense formed by the auxiliary have in the pattern AUX -ed, that is, has been.DIAGRAM HEREAnother example is the clause Food was being thrown across the room, where the auxiliary be is used in the passive pattern AUX -ed, that is, being thrown. However, that auxiliary itself has a tense formed by the auxiliary be in the pattern AUX -ing, that is, was being. The verb group in this clause therefore contains two forms of the auxiliary verb be.DIAGRAM HERELooking at this from another point of view, when an auxiliary is followed by an '-ing' form, an '-ed' form, or a to-infinitive form, that form may itself be that of an auxiliary verb which is followed by another verb. For example, in the clause She has been arrested, the auxiliary have is used in the pattern AUX -ed, that is, has been. However, be is also an auxiliary, used here in the pattern AUX -ed, that is, been arrested.DIAGRAM HEREIn this chapter, we use the terms '-ing' form, '-ed' form, and to-infinitive form to indicate either a single main verb with that form, such as liking, liked, or to like, or an auxiliary with that form together with the main verb following it, such as being followed, been followed, or to be followed.Auxiliary verbs are made negative by putting not after them, as in She is not swimming, They did not know, or He has not written to you. In spoken English and informal written English, not is often contracted to n't and is added to the auxiliary: He hasn't written to you.The interrogative of verb groups formed with auxiliary verbs is made by placing the Subject after the auxiliary verb, as in Is she swimming? or Has he not written to you? If the n't form of the negative is used, the Subject comes after that: Hasn't he written to you?Auxiliary verbs have the following patterns:
AUX -ingHe is swimming.
AUX to-infShe is to arrive at six.
AUX neg infDon't go!
AUX n infDid they remember?
AUX infDo come in.
AUX -edShe got knocked down.
AUXShe's probably earning more than I am.
cl AUX nShe hasn't finished, has she?
so/nor/neither AUX n...so do I.
AUX n -edHad I known...