Mother- tongue interference Sources of Error

a. Modal verbs are not used except sometimes in the negative to talk about things which are definitely happening, or have definitely happened. They are used when we say that we expect things to happen, or that events are possible, or necessary, or improbable, or impossible, or when we say that things did not happen, or that we are not sure whether they happened. e.g.: I can’t swim. She could be in London or Paris or Tokyo- nobody knows. I may come tomorrow if I have time. You might have told me Frances was ill. What would you do if you had a free year? I think they should have consulted a doctor earlier. b. Modal verbs have no –s on the third person singular; questions and negatives are made without do; they are followed by the infinitive without to of other verbs except for ought. e.g.: You needn’t look at me like that. He must be here by nine o’clock. Can your mother drive? That ought to be enough. c. Modal verbs have no infinitives, and other expressions are used instead, when necessary. e.g.: I’d like to be able to skate. You are going to have to work earlier. d. Modal verbs have no past forms. Could and would are used with past meanings in some cases but never to say that particular events actually happened on define occasion. e. Modal verbs can be used with perfect infinitives to talk about things which did not happen, or which we are not sure about, in the past. e.g.: You should have told me at once. Her car may have broken down. 34 Actually, there are two groups of auxiliary verb. The first includes the functional auxiliary verbs be, do, have and go. 35 They do not really have “meanings” of this kind when they are used as auxiliary verbs. 36 All of these verbs can also serve as main verbs as well as auxiliaries. Examples: I do not understand your question. We are going to visit my uncle. 37 The second includes the modals auxiliaries can, may, might, must, should, and so on. They differ from the other auxiliaries do, be, have, and go in that they have no s-forms, or ing-forms, or participles. Furthermore, they so called past forms of modals sometimes express the same meaning as the present or simple forms. They also occur in statements which refer to future time. Thus, the form of a modal does not necessarily indicate the time reference of the sentence in which it is used. 38 There serve both as structural signals and have a meaning of their own. They are never used as main verbs. Examples: We can see the zoo some weekday. Can we see the zoo some weekday? You shouldn’t try to go there on Sunday. Should we try to go there on Sunday? 39 According to Cowan, modals can be classified according to form and meaning. The form of modals can be categorized into three categories; pure modals, marginal modals, and semi modals. 34 Michael swan, Practical English Usage, Oxford: Oxford University Press, 1980. p.388 35 Eugene J. Hall, Grammar For Use, Jakarta: Binarupa Aksara, 1993, p. 11 36 Swan 1980, op cit., p. 91 37 Hall 1993 , loc cit. 38 Jean Praninskas, Rapid Review of English Grammar, Second Edition, New Delhi: Prantice Hall of India, 1977, p. 234 39 Hall 1993, loc cit.