Semi-modal verb “Need to” and the modality of obligation “Must & Have to” in authentic corpus-based English

Abstract

Recent studies indicate that the modality system of current English grammar depicts notablealteration in the frequency, distribution and semantic developments of modals and semi- modals.Research on some modal auxiliaries points toward a considerable decrease in the use of these modals(e.g. shall, must) while semantically similar phrases called semi-modals (e.g. have to, need to, begoing to) show an upward trend in use. This research paper focuses on an investigation of the semimodalverb “need to” in naturally occurring American English comparing to the root modal “must”and the semi-modal “have to”, which are mainly used for the expressions of strong obligation. As anexploratory corpus study, the purpose of the paper is to present conducted observations and makeinferences from the authentic uses of the epistemic necessity and modality of obligation in the contextof American English. All data are obtained from the Corpus of Contemporary American English(COCA) over the span of 1990-2017. The occurrence of “need to” compared to “must” and “have to”is examined through frequency and percentages, distribution by genre and year, most common verbsand personal pronouns used with modals, and modal combinations of “need to”. This corpus-basedanalysis has revealed various alternative constructions and an increase in the frequencies of theoccurrences of “need to” in the corpus, providing support for earlier studies in the field. It is clearlyseen that modality gradually gets free from central and root structures and heads toward modalexpressions which are called semi-modals forming milder means of obligation expressions.