The speaker’s judgment may be of different kinds, that is, the speaker may express various modal meanings. Modal verbs unlike other verbs, do not denote actions or states, but only show the attitude of the speaker towards the action expressed by the infinitive in combination with which they form compound modal predicates. These modal verbs may show that the action (or state, of process, or quality) is viewed by the speaker as possible, obligatory, doubtful, certain, permissible, advisable, requested, prohibited, ordered etc.
Modal verbs occur only with the infinitive. This or that meaning is to a great degree determined by communicative type of the sentence and the form of the infinitive. That is a huge problem for foreign learners of English, who make a great deal of mistakes in this field. So, the aim of my work is to show how modal verbs can be used, in what case we need one or other verb and why.
English modality can be expressed not only by modal verbs. Modality can be expressed by different linguistic means. In actual speech all forms expressing modality work together to make the meaning clear. But in every case there is some leading form that expresses the main attitude. These forms fall into four categories: phonetic (intonation), grammatical (mood), lexico-grammatical (modal verbs), lexical (modal words and phrases). But the most important from them is the third form, which includes modal verbs.
It is important to take into account one more feature peculiar to modal verbs. They all show that a certain action is represented as necessary, doubtful, etc. From the point of view of the speake, there are verbs which ‘help’ other verbs to express a meaning: it is important to realize that “modal verbs” have no meaning by themselves/ A modal verb such as would has several varying functions; it can be used, for example, to help verbs express ideas about the past, the present and the future.